He loves animals. So people who hurt animals are the worst kind of villains.
I mean, I can understand that, but sometimes those scenes are almost framed comedically. Probably not Araki's intention though.
I do think he likes violence against women a bit too much---yeah tons of random males get brutally tortured but there always seems to be a weird sexualized component when it comes to female NPCs.
Examples? The violence in the series is disproportionately aimed at men since that's what most of the characters are on both the allies and villains sides (part 6 being the exception).
I can think of J Geil and the fact he raped and murdered Polnareff's sister, but that happened in a minimally animated flashback that didn't have details, which is no different than Angelo's backstory which had male rape. Other than that, there's the magnet lady I guess? I mean, she was a seductress and there was nothing sexual about the violence committed against her.