There are lots of OW ships that I don’t like, but for the most part it’s just because of personal reasons.
I don’t like Geny/att/a because I think it’s a disservice to Zen (and to Genji to some extent). It’s just so hard for me to believe that Zen takes someone under his wing and becomes romantically involved with them. Also, I’m not personally into teacher/student dynamics because it can go so, so wrong, but I don’t think the ship in question is inherently bad. Oh, and I dislike Gen/yatt/a because two of my former friends were obsessed with it, and they ruined the characters and ship for me lol (one of the reasons why I started playing OW is because I wanted to “reclaim” Zenyatta)
I don’t like it when Sigma is being shipped to people +20 years younger than he is, because I just don’t think he’d be that kind of a person. It’s a disservice to him - or more precisely to the way I view his character. But I don’t think that people who ship him and, idk, Mercy are the worst of the worst.
I also hate Ro/adra/t, like, a lot, but it’s because so many assholes I know ship it, people treat Mako so fucking disgustingly, and I just don’t see them as compatible at all. I don’t like the age gap or their dynamic (I mean it’s fun but not in a romantic way), and I say this again - I think it’s a disservice to Mako. But I don’t think people who ship it are comparable to people who ship, I dunno, Efi and Orisa.
I mean, some of my favorite ships could have the potential to be shitty, like Max and Sigma. It seems that in canon Sigma is taken advantage of by Talon, and because Max is a member of the inner council, I truly understand that some people are not comfortable with them being a ship.
But just because there’s a possibility of a ship to be abusive or shitty doesn’t mean it automatically is.