Well, most of the use cases are pretty bad. And, like, if you're unavailable and can't write something - then that's that. People aren't accessible all the time (and shouldn't appear as they are either!).

If someone appears to be constantly devoted to publishing, but actually just slams a couple of posts into a queue, it could create unreasonable expectations.

I don't see any use of this other than creating a false persona (which won't be able to socially interact via a reply since the human is not actually available). The only valid non-evil case is what @solderpunk mentioned with random-delaying posts. But that's not the same as scheduling.

Humorous bots that post random stuff or whatnot is another kind of use, but not related to human beings trying to be antisocial.