I imagine this ending the same way as previous chat services, or the facebook group etc.
if I'm proved wrong then fair enough.
you'd think that people should be mature enough to not post spam.
but what happens is that people have some fight over some stupid thing, then they start swearing so the thread is closed,
but they can't just take the locking of the thread as a cue to stop going on about something or stop arguing, so they make a new thread, or continue the argument in some other thread they are temporarily banned for a week.
but they can't just take their week off and create a second account to continue the argument,
so then they are permanently banned.
then they'll come along with a new account and be banned a few times more.
then they'll go away for a month or two.
then they come back and try sending the admins a message saying I've changed my ways can I come back. -but they are told no, because permanent bans well they are generally permanent so their new account is also banned.
and then comes the many many accounts and the swearing and the porn, etc...
then there are the people who only sign up to advertise their site or product, or who are being paid to advertise a site of a product.
I agree with what you're saying, in a perfect world of adults and grown ups, or at the very least mature people a chatbox/shout box wouldn't need to be moderated.
but by the same token, in that perfect world the whole forum wouldn't need moderation either.