Crime novels about murders are a very popular type of book. Do you think that people read them because they’d enjoy watching murder in real life?
Also, the writing seriously is that good. I’d have completed the book if it was about watching paint dry.
I interpreted your first comment as meaning that you are supposed to hate the book because of its topic as many people seem to think whenever it is brought up.
Rowling has said a lot more questionable things, though. And even written books about her insane opinions. Calling Lolita a love story makes sense, as that is the protagonist’s point of view, even though the story is also many other things.