I think the problem isn't that we got so many new users who suck. I think the problem is that we've gotten soft and haven't given them the shit they deserve.
On top of that, we did lose people in the move, but they were all good. Wille, Scott and Edorian don't seem to come around much, and Cecropia's vanished.

I'm sure there's others, but I can't think of them.
Anyway, deciding what makes for a reason to ban an idiot is impossible to set in stone, without it being a double standard and/or not holding true at all.
"I say we ban 'insert name here,' because he's annoying. Why's he annoying? I don't know, he just is. He ruins things."
How do you make a rule based on some newbie being fucking retarded?