That’s humor, horror, and erotica for you, right there. Three genres where the success or failure of the project depends upon the effect it has on the reader. Humor that doesn’t make you laugh, horror that doesn’t make you afraid, and erotica that doesn’t turn you on — they’re all failures. And given that what amuses, scares, or turns on an individual reader varies widely from one specimen of the human race to another, it’s pretty much inevitable that a piece of writing in one of these genres is going to fail at least part of the time — and it’s no wonder that writers in those genres have a tendency to go quietly nuts.
(Or sometimes, not so quietly. There have been some spectacular author meltdowns, especially in the horror and humor fields.)