I get the feeling that a fair number are looking for one thing, find it here, throw in a request, then keep looking. If they find it elsewhere, they don't come back. This is probably also true of the ones who were in and did not participate actively, got "spring cleaned", then wanted to come back for more leeching only to find out their access was denied.
It'd be nice if we could pull our own invites back, and get the credit back to use on someone more worthy. Would save the mods some work and would also fix your piss poor attitude
You know I'm J.K. Parmin...sort of
It is frustrating as heck though to spend the time and have a credit wasted on someone you thought would be good for everyone. And it really does take time to do.