9. Hank Pym's Domestic Abuse
Despite being so-called super, almost each and every hero in the Marvel Universe has flaws. Character defects that may make them more relatable, but in some cases these have gone too far. This is certainly what happened with Hank Pym, who has one of the most infamous black marks against his name in all of Marvel history.
It first happened in 1981, when Hank took on a villainous version of his Yellowjacket alter ego. When Janet confronted him about his plans, he struck her. Ever since he has been labeled as a domestic abuser, and that is something that will never truly go away.
Reportedly, this whole thing was a mistake from the artist of the issue. Hank was supposed to mistakenly strike Janet, though how it was drawn clearly made it look deliberate. If that was the case however, wouldn't Marvel have tried to move away from the reputation given to Hank?
Instead, this label has seemingly been embraced, with it being referenced ever since. Even in Avengers Disassembled, a huge crossover event, Tony Stark viciously jabbed at Hank and asked him if he had a wife to beat. Why would you ever want to remind audiences that this is what one of your heroes did?