My understanding is that Chat Rooms take up an ungodly amount of server resources.. to the point that some website hosting companies won't allow you to run Chatroom software on shared hosting servers.
And can you imagine the moderator headache when some dummy gets his butt muted in the arena, then lurks in the BBS waiting on his 'target' to log in and go at him from there?
Sounds like an administrative headache waiting to happen.