This is just my say, but banned players should stay banned, unless proven otherwise. There is so much more better compromises than a "global unban," so I'll give in my suggestion. What I think we should do is have banned players have the privilege to appeal their bans again. You screw up, you ask for another chance. Going to an extreme was the reason most players got permanently banned, most can be easily avoided, so if they're expected to avoid punishment, they should at least do the easier task of an appeal.