The biggest problem I have with this is the wasted energy by the hellbanned.
Many of them were just too passionate about a particular issue one day. Quite a few seem to have done nothing untoward at all.
I don't really have a problem with that right up until the point where you wittingly waste someone's time because they previously wasted yours.
In asking that I'd be turning this into a discussion about deontology and I doubt anyone's interests are served thus.
However, I do take your point. It just happens that I also have a considerable problem with the ethics of reciprocal justice.