Great question that I have pondered often.

I don't think there is a subject that I can't read, they can be challenging and disturbing, but if the quality of writing is good, I can usually make it through.

A similar book that I have thought about a lot is Chuck Palahniuk's Fight Club. When I first read, I just didn't get it. It just seemed like gratuitous violence for shock value. But I saw with it for awhile and reread. I felt differently after the second reading. I don't think the book could have expressed such primal drives without the gritty, graphic violence.