I don't have the urge to play a bad guy. If I did, I'd maybe replay Mass Effect?

I don't think there's necessarily anything wrong with you, just like how I don't think there's anything wrong with bdsm practitioners.

This is interesting because when I was a kid I would always try to do every bad thing the game would let me because I found it hilarious that in the context of the game there could be no consequences for bad behavior. My favorite moment was in KOTOR during a trial where I committed numerous crimes, went on trial for those crimes as part of the story, admitted to my crimes proudly in a court of law, and was let off the hook for story reasons. Now when I play games I have more fun playing heroically and trying to help out as best I can because that's what I have more fun doing and would find trolling the hapless npcs boring since I used to do it so much.