If that community doesn’t push the bad apple out, it will be a dead community soon enough. Might as well leave now if the moderators are unwilling to take action.
Either a community pushes out the negative, or it withers and dies:
http://blog.codinghorror.com/the-bad-apple-group-poison/
http://blog.codinghorror.com/dealing-with-bad-apples/
Ignoring problem users is a short term and short sighted solution.