Sometimes, a trope isn't the tree. It's the whole forest.
That is, when you see something used in fiction, it can seem to not mean anything. It's an artistic choice on the part of the creator, but it has no actual meaning beyond that and you might be tempted to label it "not a trope."
Until you look at a whole genre, or even all of fiction, and notice that this particular artistic choice happens a lot. A lot more than it ever happens in Real Life, in fact. It's nearly universal to a genre.
What you have here is an Aggregate Trope. It's a storytelling pattern, but that pattern only becomes apparent when you take all the examples as a whole rather than look at individual examples. The key word here, is "tendency".
Compare Garnishing the Story (in that the pattern is completed by the notion that the elements improve a story by their inclusion).
Tropes that are only a trope in aggregate:
- Acceptable Feminine Goals and Traits
- Adults Are Useless
- All Abusers Are Male
- All Gays Are Pedophiles
- All Men Are Perverts
- All Women Are Lustful
- All Women Are Prudes
- Always Identical Twins
- Black Dude Dies First
- Bury Your Gays
- But Not Too Bi
- But Not Too Black
- But Not Too Evil
- But Not Too Foreign
- But Not Too Gay
- But Not Too White
- Double Standard: Abuse, Female on Male
- Everybody Is Single
- Everyone Is Bi
- Everyone Is Gay
- Fandom-Specific Plot
- Geek Reference Pool
- Girl-on-Girl Is Hot (when paired with hate for Guy-on-Guy Is Hot) note
- Girls Are Really Scared of Horror Movies
- Heroes Prefer Swords
- Heroic Build
- Hollywood Beauty Standards
- I'm a Man; I Can't Help It
- Improbable Infant Survival
- Most Common Superpower
- Men Are Generic, Women Are Special
- Men Are Tough
- Men Get Old, Women Get Replaced
- Minorly Mentioned Myths and Monsters
- My Girl Is Not a Slut
- Never a Self-Made Woman
- No Bisexuals
- Nothing but Hits
- Obvious Crossover Method
- Quantity vs. Quality
- Real Men Hate Affection
- Real Women Don't Wear Dresses
- Seldom-Seen Species
- Small Reference Pools
- Small Taxonomy Pools
- The Smurfette Principle
- Sour Prudes
- Stock Dinosaurs
- There Are No Therapists
- Token Lesbian
- Transgender Fetishization
- Unto Us a Son and Daughter Are Born
- Vanity Is Feminine
- Vasquez Always Dies
- Villains Act, Heroes React
- Wet Blanket Wife
- Women Are Delicate
- World of No Grandparents
- You Have to Have Jews