The seedy world of comics

The majority of graphic novels and comics I have seen have a negative, distorted view of things. Besides the rampant sex and violence that is seen everywhere, there are the monstrous, twisted visions of evil and post-apocolyptic scenarios. I am somewhat fascinated by these things myself, but I have to wonder what purpose it serves to dwell on these things. Maybe that is the only way to get readers interested. But I think there needs to be a sense of contrast for this to be effective.