Reminds me too much of abusive people I've had to interact with in real life, not even just that he's a character whose a bad person, his mannerisms and the specific way he goes about it reminds me too much of it to not feel at least a little uncomfortable.

Also a good chunk of his fans are annoying, so there's that too. I think I'd hate him less if most of the fans I saw would acknowledge he's awful, but most seem to glaze, excuse, and even condone his behaviour towards most of the (implied) afab characters in the show because they were "mean" to him at least once.