Bans on this site are fundamentally subjective and up to the discretion of the moderation team, which is a good thing. On the Schlog, we constantly argued about the rules and who should be banned or shouldn’t and we saw how that turned out. It’s much better for the mods to simply ban those who contribute negatively to the site, even if they don’t really break any rules.
As for the CX2 situation; I trust the mods' judgement in their decision, though I am saddened that this site and its culture weren't able to counteract the obvious grooming that happened to that guy.
I think that, in the future, when such a person appears again, we should make more of an effort to undo the damage inflicted on such people. Though of course if our efforts have no effect, there's no point in keeping such a guy around.