Why indeed. I'm a full-blown horror enthusiast (as you're probably aware), and I'm not snobby about gorefests when done well. But horror films have to be scary to start with, and the Terrifier films aren't terrifying. Merely meaninglessly repugnant (like the Human Centipede films). Martyrs is an intensely brutal watch, but again, it is at least about something. These films aren't.

On a related note:

Are Horror Fans Desensitised? by Simon Dillon | Writers’ Blokke (medium.com)