[Star Trek: Spock Prime]For example, I've been reading a lot of Star Trek Kirk/Spock fanfic recently, mostly from the more recent movie verse, as I'm not super familiar with TOS. Anyways, I really just do not like Spock Prime (or Ambassador Spock aka the older AU Spock) as a main character. I don't mind him acting as a side character/mentor etc. But I just don't like him when he become integral to the story.
I think this is mostly because, if he is a big part of the storyline, it is almost always because he had a romantic bond with his Kirk, which then cause all kinds of complicated feeling for this Kirk and Spock. And with my OTP, I just don't want them to have strong emotional romantic attachments to anybody else, even if it is and AU version of themselves. But even if the attachment is subtle and not physical, it oftentimes takes an amazing story, and makes it just okay for me.
[Harry Potter: Scorpius Malfoy]And this happen to varying degrees in other fandoms too. In Harry Potter fics, I just cannot get behind Scorpius, as a character, but especially in a pairing. I can handle him in H/D kid!fics, but I prefer him to be younger. I've read a few Albus/Scorpius fics, but I've just never been able to get into them. I LOVE Draco/Albus, but I've tried reading Harry/Scorpius and it almost actively bothers me (which is super rare for a pairing). And I thought maybe I just don't like the taboo of Harry being with a younger somewhat forbidden character. But I am all about Harry with pretty much any of his children, so it's not like I'm putting Harry on a pedestal.
And I just can't even at all read Scorpius with James or Teddy. Probably because James/Teddy is my next gen OTP and if they are going to be with a guy, they are going to be with one another. Maybe that's my problem. My headcanon for Scorpius is that he is straight (or mostly straight) and he is so often written with guys, even as a side pairing in fics, that I just would rather not read about him at all. I feel bad, because he hasn't really done anything to deserve my dislike.
[Teen Wolf: Laura Hale]In Teen Wolf fic, it's Laura. I think this is because she is almost neevr characterized the way I see her, and she just comes across as really bitchy and pushy and selfish.
IDK. I've just noticed my intense dislike of certain side characters cropping up in stories a lot lately. Sometimes it's honestly to the point where I almost don't even want to rec the fic, because the character and/or their story arc totally ruined things for me. But I feel like oftentimes, my dislike of characters is not at all in line with fandom's general view of them.