The moderators can. The users can’t (and shouldn’t be able to).
I was specifically responding to why paying customers wouldn’t be requesting it. In a nutshell, the paying customers aren’t the same use case as general users, and wouldn’t request features like this unless their users were being especially vocal about it.
In most cases, if their users were being especially vocal in requesting this kind of thing, it’s likely that there would be a specific user who was being disruptive enough that the admin could ban that user. So demand for the feature is self-limiting, but that doesn’t give the actual worth of it since the feature itself is primarily useful for situations where a particular person isn’t enough of a disruption to warrant an outright ban.
It’s really not meant to be, as far as I’m aware. It appears to be a way for individuals to deal with problems they may have, without requiring any others to agree with them and without appreciably inconveniencing the other person involved.
(I should add that I’m unlikely to use this myself… but I can definitely see why people would want the option.)