In that discussion you seemed to agree that there's not much we can or should do about it; you seemed to be indicating that you were just contemplating the phenomenon, rather than complaining or arguing that something needed to be done.
For what it's worth: the “celebrity” effect works both ways. Sure, some members of the community may be more willing to give them a pass. But other users will be more motivated to downvote and/or flag, even if the comment is relatively benign.
Walter isn't some quarter wit user who doesn't know that he's doing here.
He's posting trash and getting away with it because of his reputation.
It's dismaying.