Well, yeah. That entire deal right there is the reason that it's a bad idea for designers or authors to have messageboards that other people can post on.

You come in trying to have a fun discussion, and then somebody gets rude to you, and you either have to get rude back, and be labelled an egotistical jerk (for firing back) or just bear the abuse and hope that your fans beat the snot out of the rude person.
I've seen it happen on RPG boards. I've seen it happen on TV boards where the writer/producer posts. I've seen it happen on author boards. Never pretty, and no real graceful way to deal with it -- aside from, say, not allowing rude posts.