Hey remember when Ronaldo decided he wanted to be a part of Steven's life and be one of the crystal gems, and he almost killed himself doing so, and in response they not only shouted at him for being selfish and trying to make THEIR club that he was not and could never be apart of about him; and then they cut him out of the show entirely and he never got to do anything else?

Eeeeh, I don't know. Genocide/mass murder could happen in real life.

Also all Kevin did was hit on a non-binary who isn't comfortable with being hit on and just be a jerk. Asshole, sure, but not on the levels of killing people.

Basically this is comparable to how Twilight basically still hold some resentment towards Trixie for being boastful, yet pretty much forgives Starlight for basically communism and rewriting the universe to suit her needs.