I just suspect it just rubs people the wrong way by saying the community forum is going to fail and then on top of that and asking how to cancel the account because you are being nice to the admins.

But to answer the question I don't believe there is a way currently.
Its vBulletin thing.

This post is about that very same thing.

http://www.vbulletin.com/forum/showt...is-her-Account

I think the main issue is keeping people user posts, because for better or worse loosing posts because someone removed their account can disrupt the the flow of old topics that might have had useful information in them or have the entire topic removed in the process.