Not the dev, but our decisions are made based on what benefits the community as a whole. We aren't going to throw the community under the bus in the case one dude can't get his act together.
Not to mention, we have and do give people second chances (though this guy's on his 4th if you consider the verbal and official warnings leading up to his ban), as long as they actually show a proper willingness to change. He has shown no such thing.
If we could trust him to not do the same thing that got him warned and banned in the first place, we would unban him properly. Else, it doesn't really make a difference whether he's on the same or a different account.