These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The show itself is also another example, through it was very popular in Japan after the compilation movies were released and started the Gundam franchise, many blame the reception of the first Gundam series for the downfall of the Gundam franchise in the West.
Although that probably had less to do with the story and more to do with the aesthetics, the poor animation was off-putting for younger viewers who were used to Gundam Wing.
Dark Is Not Evil: Dozul Zabi during his death scene appeared to manifest a visibly sinister aura (which was even scarier looking in the TV series). Strangely enough, Dozul was one of the more likeable Zabis. He cared about his men and was a loving family man. Fans tend to interpret this as an aura of hatred. While he loved his country and his people, he hated everything the Federation stood for.
The mobile suit Acguy has large number of fans who consider its big head, stumpy limbs and plump frame to be Ugly Cute. Its derivatives, the even more bizarre looking Agg, Juagg, and Agguguy, aren't horribly unpopular themselves considering they were never actually on the show.
Sleggar Law appeared in only a handful of episodes yet is incredibly popular. In fact legendary anime director Noburo Ishiguro loved Sleggar so much that he admitted to modelling Roy Focker from Super Dimension Fortress Macross after him.
Evil Is Cool: Zeon gets a lot of love from the fanbase. And there is of course, Char Aznable. It would be hard for him to be a bigger dick. It would also be hard for him to be a bigger badass.
First Installment Wins: Pretty much. Of all the UC series it's always this period that gets side stories, video games, and such. Even though Zeta Gundam was even more popular at the time it a shadow at times these days.
It's Star Trek syndrome. While the sequel series may be vastly superior, the original show inspired a fandom.
A Federation ship carrying children is sent out into dangerous situations. Years later, Star Trek: The Next Generation would do just that on a weekly basis.
Ho Yay: Fans get giddy at the Char and Garma subtext, especially during the shower scene and their arranged plans.
Hype Backlash: After listening to UC fans promote Mobile Suit Gundam 0079, it can be somewhat disappointing for some fans of other Gundam series to watch the show. Not because it's bad, but because it cannot live up to the hype its fans create for it. The same can be said for individual characters such as Char Aznable and Amuro Ray.
Love to Hate: Char is this to the parts of the fanbase who aren't giving him leather pants. Gihren Zabi arguably qualifies as well. There's no doubt he's a total bastard, but he's just so good at it.
Magnificent Bastard: Char, he has many moments of Magnificent Bastardry throughout the series, but one of his best is when he leads Garma Zabi into a trap, politely calls him on the phone, explains his motives, tells him goodbye and leaves him to die. YMMV on wheather you lose sympathy for Char as some see it as his Kick the Dog or Moral Event Horizon moment.
"Not even my father hits me!". God knows how many characters in other series utters this line because of Amuro saying it.
"This is no Zaku boy, no Zaku!"
"Blame it on the misfortune of your birth"
Misaimed Fandom: Yes, the Federation has corrupt leaders. Yes, Zeon has many good, moral, people who serve it. Yes, the Titans are bad. That being said, it's a little scary how many fans will knee-jerk a SEIG ZEON for a regime that murdered, not millions, but BILLIONS of people and continue to wipe out metropolitan centers every few years... FOR FREEDOM.
This seems to have seeped in writers of many of the UC side stories where the majority of Zeon characters are presented as the heroic ones while any good characters in the Federation are typically a Token Good Teammate, which ignored there was fairly even balance of sympathetic characters in the original series on both sides, the worst characters were in Zeon.
What really makes Char's crossing of the moral event horizon work is that he didn't just kill Garma he also killed of the ENTIRE CREW of the Gaw that Garma was on. And THIS is coming form a man who had been shown to genuinely morn the loss of his subordinates. Chew on that for awhile.
Gihren Zabi crosses it at Garma's funeral, when he turns his younger brother's sendoff into a self-aggrandizing political rally, then reveals himself as a Complete Monster when he murders his father.
M'Quve arranging for Ramba Rall's death
Narm: The crew crying and blaming themselves for Ryu's death. Changed for the compilation movies, fortunately. In the movies, Amuro just beats up Hayato for letting Ryu go into battle.
While the compilation movies may have toned down the banshee-like wailing of the White Base crew, Ryu's death in itself lost a lot of its impact. Tomino shoehorned it in for continuity, at the expense of the plot, and Ryu's sacrifice came right after Matilda's death by similar means. The White Base Crew (and Amuro) spend more time mourning Matilda than they do Ryu, who in the series was so mourned that Bright had a PTSD type breakdown and couldn't captain the ship for several episodes.
The symbolic images involving the Newtype powers can get very ridiculous. Near the series it looks like Amuro is tripping balls rather than feeling traumatized due to his girl's death.
Never Live It Down: Kai Shiden is labeled a Dirty Coward by most of the crew early in the series for his bitter complaints about the situation they're in, despite the fact that he repeatedly undertakes dangerous assignments when necessary.note And after the war, he's left the danger of a MS cockpit for the safe career of war journalist While the other characters eventually realize their mistake, the majority of the fandom seems to have ignored that and consider him a spineless jerk.
In other circles however, he's an Ensemble Darkhorse with a level of popularity that surpasses even Char Aznable. It helps that, come Zeta, he's effectively the Gundam series equivalent of James Bond.
Seinfeld Is Unfunny: Inevitable, given the number of homages the later shows in the franchise did, it means many plot points in the show don't stand out now as much as they did when they were first done. The show wasn't very successful when it initially aired, in fact leading it to end three episodes earlier than originally planned, meant it didn't have the animation budget that later Gundam shows did, which can be clearly seen in how its animation it a lot less detailed and a lot slower paced.
Squick: In the novel version, aside from the gross plot changes, Word of God states that Amuro's crush on Sayla culminated in him making a locket out of her pubic hair.)
It should be noted that Amuro himself initially thought this was disgusting, but was pressured into it by Kai and Hayato. It's apparently a combat pilot superstition that if a pilot gets into a relationship with a woman he must take an "Amulet" with him on missions or risk bringing misfortune and death on the entire squad. Though there's also the implication that Kai is just making it up to screw with him.
Strangled by the Red String: Amuro and Lalah's relationship just comes out of nowhere, as does their instant attachment to one another. The series justifies it, what with their Newtype powers having caused them to identify with one another, but that doesn't help make the relationship any more real to the audience. The strangling New-Type would become a tradition in Zeta Gundam.
Wangst: Amuro can get pretty whiny at times. He has his reasons, of course, but even so.
And it should be noted that he stops his petulant whining about two-thirds of the way through the series.
Hayato's as bad, or worse. His entire personality is based around resenting Amuro for being better than he is, and whining like a bitch whenever Bright praises the latter's performance. Perhaps his wangstiest moment comes following the latter's desertion, when he's so mad that Amuro wasn't executed for it, that hedeserts. You go kid. That'll show them.
What an Idiot: Hayato deserting when Amuro wasn't executed for deserting. Logic clearly was not involved. Thankfully for both of them they weren't part of the regular military at that point and Ryu even reasons to Bright that they were on the spot draftees, so it would be too harsh to apply strict military rules to them.
What Could Have Been: The legendary "Tomino Memo", published in a 1980 book, details the original 52-episode plan for the series. Hitting the high notes: Kycilia attempts to take over Luna 2, but gets killed as Solomon falls. There are a lot more Newtype pilots who end up getting slaughtered (including one who kills Lalah for "consorting with the enemy"). Bright gets the hots for Degwin's Sexy Secretary, who turns out to be a spy and whom he ends up killing. Amuro personally guns down Gihren, and Char refuses to leave A Baoa Qu as it self-destructs, apparently dying. There were also a bunch of new mobile suits, most of which were drawn up and became part of the rejected sequel proposal MS-X.
One of the major points of the Gihren's Greed video game series is to let the player explore these. For example, a Zeon player can choose to give Ramba Ral his Domsnote in canon. M'Quve denied the request entirely for political reasons, which leads to his defeating White Base and capturing the Gundam. More recent games take this a step further and allow you to save characters like Ryu, Sleggar, Garma and Kycilia from canonical deaths, making them usable during the events of Zeta Gundam (complete with aged-up character portraits).