Why won't most porn search engines let you EXCLUDE search terms?

Rant:

With regular search engines, you can usually put a minus "-" in front of a word in your search, and then you won't get results that contain that word. With porn search engines, that usually doesn't work.

Why?

Don't the people running the porn search engines ever get the idea that some of their users might have things that turn them off, and that they might want to avoid?

All too often, when I type some of my favorite things in porn into a porn search engine, I already know before I hit Enter that most of the results will be either from studios I don't like, or have something else about them that I don't like, or have something about them that makes them simply not what I'm interested in. It's pretty annoying.

[Bert76]

I am wondering the same thing for years now!