My two cents,
I don't have a problem with Jo joining the forum, Shutter. Her posts were sometimes very long and hard to understand, but I could usually just skim them. As it true with anyone, if they can behave, I welcome them. Personal attacks from anyone should be cause for dismissal.
The problem with others was when they injected themselves into every discussion, repeated the same story over and over again, called other liars and challenged others to constantly prove their case without feeling the same responsibility himself. That, to me, was what really dragged the other forum down.