Exactly that most places actually do ban ‘moron’ in official communications and have done so for ages. It’s an extremely ableist term, it’s does not simply mean “stupid”.
I have to say, most places that go so far as to ban moron also ban stupid.
Who's banning? None of the lists the author talks about actually bans any language. They advise.
I think the point is that if someone does not comply with their advice they might have their life impacted in a negative way, can't get job, grants, ostracized, etc. Which de facto becomes a ban.