IMHO, hellbanning is both cruel and damaging - the community may lose potential interesting contributions.
For example, I've watched a bit of what losethos wrote for his 64 bit OS - it's an interesting approach. There are not so much at the time, but he seems to submit articles time to time.
I sometimes even read losethos comments, which sound to me like hybrid talk from Galactica. Words linked by references obscure to me, but which still might have a sense (the old greeks did believe in Oracles, so do I. My fault: I shouldn't be a believer, and just accept the traditional medical theory who claims it's just nonsense)
I also have showdead enabled, mostly because I like to look back in hellbanned posters histories and see why they were hellbanned. In very few cases do I find someone for which I don't understand the hellbanning. In those cases I usually try to give the person a heads up, but in the vast majority of the cases I realize that the person was excessively abusive, spamming their pet project, participating at a stereotypically "reddit" level, or otherwise submitting crap.
(Also, I am pretty certain that losethos's comments are computer generated. He thinks that a god talks to him through a RNG when he initializes markov chains with the bible or something... Any meaning derived from what he says after "god says:" is likely just apophenia)