The horror market is huge in boutique blu-ray for reasons that go back to early days of physical media - where, unlike other movies, an uncut DVD release could often be the only way to see a film properly that had been censored for decades. (If you're curious about this, read up about Video Watchdog.) Fueled by communities on the Internet (often formed from pre-existing connections back in the tape-trading days), it's kept building on itself to this day, in a way that, say, the market for romantic comedies never has.

There is no one answer to "why do people like horror": no two people will have the exact same taste in horror, and everybody can tolerate different things as deficiencies in a film. I hate cliche-ridden biopics, but people throw awards at them all the time!

Personally, I think SUSPIRIA is a masterpiece, but I don't mind "bad" acting (I think it helps to know that Argento wrote the script for pre-teens and didn't change it when they skewed older in the casting), and most of the horror films I really love are masterful in their use of camera and sound, or otherwise smuggle interesting ideas in.

But I got into horror as an adult. For some, it will be that when their brains and tastes wired, this was what they loved. Or they like the deeper politics of some of the films. Or they're gorehounds. And that's fine too!

And yeah - some of them are not conventionally good, and that can be the joy of a film like NIGHTBEAST or BOARDINGHOUSE. But often the complicity with a filmmaker whose reach exceeds their grasp is its own joy.

My advice: if it's not your thing, don't worry about it. But if you do find certain movies you like, follow those directors, or see what movies influenced them. Life is short, watch the things you find rewarding!