Like other people have said it really depends on the person.. Someone who has been banned could have learned the site and different things and over a long time become a respected member and Bungie would see this.. Or they could never change. Someone who hasn't been banned could also be a well respected member over time and it would take less time for this because of how they act and they could be a generally nice and thoughtful member who knows their stuff. On the other hand they could be a jerk and just be hiding behind a mask.... That is why Bungie is so could at choosing people they now what to look for and have the wisdom for it. Its a pretty tough question though.