Talking to younger folks into horror, they always refer to realism. I think the US lost a lot of its romanticism after vietnam & watergate. That would only explain why horror is different since the 70s. I'm too romantic, so I'm not that big a fan of recent horror, but there's been a huge resurgence since around 1999. Maybe someone smarter than me can explain why guys like Fulci & his followers and the Japanese have actually taken over the romantic strain in recent decades, because I think they have, but can't explain it. There's probably a global connection here I also can't expound on, something along the lines of how non-Anglo sensibilities rule in horror these days. That and realism.

It's just a half-baked sense I have, not even a kernel of an idea.

The studios and start part is probably just the way the business has evolved. Music did the same.