If you wear a real fur, you must be evil or immoral. That's the only explanation.
This is not about the politics of wearing fur, but simply how the mainstream media portrays it since the mid 1980s. In that time, groups such as PETA finally gained some traction, through celebrities building up a Band Wagon Technique. Wearing animal fur was considered the mark of evil. Leather is usually given a pass since the rest of the animal was killed for meat anyway, "and would you tell a 300-pound biker to give up his jacket?"note footnote in a novel by Terry Pratchett, but fur industry revenues went into a decline through the late '80s and '90s.
Yet this didn't last long. Other celebrities came along and decided they liked fur, particularly rappers and hip-hop artists. Combined with sites like eBay making fur coats affordable, fur is more popular than it's been for decades. Just go to photo sharing sites and look up "Fur coat", "mink", and even "pimp coat".
Of course the media doesn't reflect this. Partly because it's Still The Eighties, and partly to satiate the remaining anti-fur celebrities, mainstream media since the mid 1980s has an unwritten rule about fur: it's a sign of corruption. Not the fur itself (barring bad horror movies), but of what you did to get it.
So wearing fur in media has now become part of the Hollywood Dress Code, often to show how corrupted characters have become. Wearing fur identifies you as:
Emma Frost from X-Men is a definite Rich Bitch (although she wasn't as much of an actual bitch as she suddenly became). Her most famous outfit has a cape with a huge white fox collar (assuming this outfit was made for real). However, she first appeared in 1980. Yet when she turned into a hero, it was the early 1990s, and her outfits didn't include fur.
Genius Pixie Opal Koboi in Artemis Fowl: the Opal Deception has fur-covered seats in her custom-built luxury shuttle, as a sign of her leaving behind the fairy world (most fairies are vegan), and embracing the human world. It should be noted that leather doesn't get a pass in this setting, either; had the seats been made of leather it would have been just as abhorrent to the fairies. However, even Artemis is disgusted by the fur seats.
In Ace Ventura: When Nature Calls, Ace confronts a woman wearing all kinds of animal products, who dismisses him as "another activist," and goes on "There's nothing wrong with enjoying the fruits of nature. I suggest you try it sometime." Ace does so, punching her husband and then dancing around with the man on his shoulders.
In The Stallone/Banderas film Assassins, Julianne Moore's animal-loving character spray-paints a woman's fur coat while standing in an elevator and making a "shhhhh" sound to mask the sound of the spraycan. The implication is that she's a free spirit while the fur-wearing woman is a Rich Bitch.
Even though Dallas and Dynasty started in 1978 and 1981 respectively, it seemed in later years, these shows and their spinoffs gave most of the fur coats to the Rich Bitch characters.
In the musical episode of X-Play, after receiving lucrative contracts to produce their own games and stressing out factory workers to make it, Adam and Morgan go from snarky video game reviewers to rich snobs. The first shot of them after the factory scene starts with a close up of a pair of high-heels stepping onto the sidewalk, panning up a fur coat, and then to Adam's head. Morgan joins him a second later in a business suit.
In an episode of Designing Women Suzanne Sugarbaker (played by Delta Burke) is criticized for her new fur coat she shows off by her sister and after being attacked by animal rights activists ends up with a broken arm and refuses to have the coat cut off of herself to set the arm resulting in her spending weeks in the coat while her arm heals. At the end she swears off fur simply because she spent so much time trapped in it.
Fate/stay night'sGilgamesh becomes the male example when he appears in a pimped-out fur coat as his 'civilian' dress. This wasn't part of his uniform when he was summoned into the world, but he went shopping and consciously selected it. Personal traits include haughty, disdainful of all others, proud of his vast riches and in fact considers himself owner of everything in the world — does he fit the Rich Bitch aspect yet?
Mallory Archer from Archer has a regular account at a furrier. Definitely a Rich Bitch, often seen in furs.
Indirectly done in Family Guy, in the episode when Lois is mayor. She agrees to allow pollution so she can buy a fur coat. She relents, though, and doesn't have to give back the coat, but the coat is never worn after that.
The Ice Princess in Batman Returns is a total bimbo. While the villainous Catwoman doesn't even wear leather —she wears vinyl— so she lives, the Ice Princess, well... For wearing fur, Redemption Equals Death.
Max Shreck and his son Chip also wear fur-lined coats in the movie, but they're more the Rich Bitch type.
In Sister Act Deloris gets a mink coat from her mobster boyfriend and is upset that he's actually given her his wife's fur. She goes to confront him about it and witnesses a murder than that sets up the movie. The fur was used to show Whoopi's character was a bit The Vamp at the beginning of the movie and to show that her boyfriend was mobster.
In Miss Pettigrew Lives for a Day, Delysia Lafosse seems to like wearing fur. She even comments on how nice it feels on the skin. However, she makes this comment when she's supposed to be in the middle of a "serious" conversation. Then again, this may not count if that scene was in the original book, which was published in 1938.
In The Avengers (1998), Mrs. Peel's clone wears a fur coat when she tries to murder Steed with a spear gun and pistol.
Earlier chapters of InuYasha had the titular hero and Kagome confront a pair of minor demon brothers who were the personal enemies of fox youkai Bratty Half-Pint Shippo because they were responsible for killing his father and wearing his fur.
In the 1967 film of Doctor Dolittle, the doctor has a somber-but-angry musical number toward the middle of the movie, "Like Animals" where he sings about mankind's exploitative, demeaning, and cruel treatment of animals to a full courtroom. At the end of the song he specifically addresses some upper-class women watching the proceeding, all of whom are wearing fur.
"When you dress in suede or leather, or some fancy fur or feather / did you stop and wonder whether for a fad, / you have killed some beast or other? And you're wearing someone's brother? / Or perhaps it's someone's mother in which you're clad."
Little Red Riding Hood in Roald Dahl's Revolting Rhymes shoots The Big Bad Wolf to get herself a fancy new coat. She is later called by a certain little pig who is being menaced by another bad wolf; unfortunately for the pig, her greed for accessories made out of animals doesn't stop at a second wolfskin coat.
The WWE tag-team MNM, a pair of heelish celebrity hangers-on, were known for their fur coats and boots. Oddly enough, their manager, a Rich BitchVamp by the name of Melina, never wore fur, though she does seem to be fond of animal prints. One member, Johnny Nitro, kept the furs even as he transitioned to his new gimmick, an odd cross between the Jerk Jock and the Warrior Poet by the name of John Morrison.
An episode of Braceface deals with a short tiff between Sharon and Miranda when the former plans to participate in a fashion show wearing fur clothes. In the end, Sharon decides to accept Miranda's decision, whereas Miranda has switched out all the real fur for faux fur.
The Simpsons has Mr. Burns; despite the fact he is normally only seen wearing his trademark business suit, the episode "Two Dozen & One Greyhounds" reveals he has a real fixation on the most unusual sorts of fur for his clothing. Besides the greyhound fur tuxedo he plans on making from the puppies he stole from the Simpsons, his wardrobe includes a vest made from the chest of a gorilla, a sweater made from Irish Setter fur, a hat made from the skin of his last pet cat, evening wear made from the skin and wings of vampire bats, slippers made from the feet of albino African rhinocerii, grizzly bear fur underpants, literal turtleneck shirts, a beret made from the head of a French poodle, two formal suits (one single-breast, one double-breast) made from the breast-feathers of robins, and a set of loafers made from gophers. He also comments that when he made the loafers, the alternative would have been skinning his chauffeurs.
The Road To Wellville features characters in the early 20th century, acting like moderately militant PETA members. Whether people were actually like that at the time, it seems likely that this was more of a bow to politics at the time the film was made.
There were indeed animal lovers at the time, but for the most part they only protested against blatant cruelty to animals.
It gets a bit ridiculous in Harry Turtledove's Crosstime Traffic novel Gunpowder Empire. The two main characters will literally stop whatever is happening just to talk about how nobody wears fur anymore and how polite society sees it as repulsive. This doesn't just happen once, but about 9 times in a 200 or so page book. The alternate timeline never saw the Roman Empire fall or technology advance much past our timeline's 400 AD. Still, even if they're in northern Europe and freezing, "FUR IS EVIL!"
Notably, the narration points out the hypocrisy involved. It's something of a hallmark of Turtledove to have characters express a viewpoint, while the narration points out the flaws and cultural viewpoints that shade that belief.
Played with in a Josie and the Pussycats comic. Alexandra has a line of fur coats, which Melody says is cruel. Alexandra explains that they are manmade, and starts naming off the synthetic ingredients. Melody doesn't get it and demands she free the Orlons.
In the EC Comics Science-Fiction SuspenStory "What Fur?!", in a space-faring future where skunks are being driven to extinction due to demand for their pelts, a furrier seeks to make a killing on a little-explored small planet which is crawling with skunks. Unfortunately, this planet turns out also to have giant furry aliens who like to wear human skins around their necks.
Inverted Trope in Hell on Heels: The Battle for Mary Kay, Mary Kay wears fur, and even gives a black mink coat to the best saleswoman each year. The film portrays these woman as hard working, while The Rival, who eventually makes her company fold, never wears fur.
Tamora Pierce prefaces at least one of her books with a foreword telling animal rights groups that wearing animal furs is inevitable in a middle ages-based fantasy setting, and doesn't necessarily condone them in real life.
In Brothers In Arms by Lois McMaster Bujold, Miles Vorkosigan buys a "cat blanket" which is made of fur. The subversion is that the blanket is a genetically engineered living organism. It doesn't shed, is self-cleaning, lives via photosynthesis or microwave absorption, purrs, and snuggles up.
Still, Miles, Ivan and later Mark, are by turns delighted and creeped out by it.
In one episode, Phoebe on Friends got a fur coat as a gift and, being the hippie of the group, constantly complained about how evil it was - until she tried it on and decided it looked good. For the rest of the episode, she justified wearing it using very spurious and shaky logic, and eventually she gave it to a hobo when a squirrel made her feel guilty.
Veronica Marswears a coat with a faux-fur collar while talking to some animal rights activists, realizes it, and takes it off. One of them sneaks behind her and moves to chop the collar off; Veronica catches her, shrieking "It's fake!" (This is probably important to actress Kristen Bell, who is herself one of the sane-ish kinds of animal rights activists.)
Given the level of technology in Avatar The Last Airbender and where they live, Sokka and Katara are apparently wearing animal furs to keep warm, with no stigma attached. Although there was this dialogue in Bato of the Water Tribe
Katara: Bato! It looks like home! Sokka: Everything's here, even the pelts! Aang: (unenthusiastically) Yeah... nothing's cozier than dead animal skins.
Of course, this makes sense given that Aang is a vegetarian and cares for animals in general. Using animal products as a matter of practicality is one thing, but it has to irk him slightly for his close friends to be EXCITED over it.
A canon comic features a fur salesman using synthetic fur and going on a rant about the cruelty of real fur.
In one episode of The Itchy & Scratchy Show, Itchy (the mouse) skins Scratchy (the cat) alive and sells Scratchy's fur-covered skin to a Grande Dame. Scratchy, sans skin, accosts the Dame and takes his skin back, wrapping it around his neck. He leaves the store and is immediately pelted with red paint by a PETA-type group holding signs like "Fur is Murder."