I haven't either, to be honest.
The thing is, you've ONLY just started to acknowledge that it's only your perception of emo fans. It's not all of them. Infact, I'm gonna go so far as to predict that the number of emo fans who cut aren't nearly as much as people predict.
Number two, people who cut don't usually cut because of the music they listen to. They cut because they've (psychologically) got alot of bad mental issues and drive themselves into intense physical sensation to get rid of it.
-AC