I'm not sure what this derail is about, but I'll humour you.
Every knows the villain has a sad back story that led them to their evil ways. Some sadistic mother, or friends that tormented them to the point they snap and start killing people.
And everyone knows that the only people that die, the "victims" in a horror movie had it coming. If you're good and virtuous you don't get killed. That's the rules. Haven't you seen Scream?
None the less, violence is violence, and movie violence, for what ever reasons, is very common. Horrorcore is just a stage show with a crappy rap sound track.
It's fake. Make believe. A bunch of characters literally screaming bloody murder and spraying Faygo onto a crowd of crazed fans.
You go, you get crazy, you see the show and you go home.
edit: I just realized you say you
are familiar with Horror. I'm calling BS, you don't even know the basics.