If they had a valid reason, would they still be a villain?
Um yeah? Valid reasons like the main characters unintentionally doing something to them that utterly ruined their life and that's why now they want revenge which is way brutal than anything the main characters ever did to them? Something like that?
At least the stupid hacker girl had some good reason but what about the rest? What about the bloody psycho mother?
Let's say the mother takes pleasure in harming others but at least we could see some people fighting for themselves and standing up for themselves and shit (not just her husband). That is some people not falling for her obvious manipulation and shit. But other than that, what if the psycho mom just harmed strangers and not her kids and spoiled them like crazy or treated them like a good parent at the beginning at least? Wouldn't that be an interesting villain? Who's just good with her own blood but because of her fetish, she experiments with strangers and tortures them and them only??? But then her kids figure it out and they aren't supportive of that and so that's why she may start to act all evil towards them too?
Then what about all the random ass characters who took things way too far with uichii despite the fact that he never did anything to them. I get it that people may hate u for no reason, I do that too but who's actually going to go through the effort and length of making sure that the person that they hate, obviously for no reason, is going to have as miserable of a life as possible? Who got that much time and energy on their hands? Take that masochistic bitch for example. That bitch simply didn't need to exist in this story, in the first place but hey, author knows best.