Dark books do appeal to kids because they have nice, sheltered lives - and they also appeal to children who are going through pretty hard times themselves.
Certainly going back to Sherlock Holmes we have a tradition of forensic science featured in detective stories.
The difference between the old ballplayer and the new ballplayer is the jersey. The old ballplayer cared about the name on the front. The new ballplayer cares about the name on the back.