There's something to be said for including everybody. Sometimes, that's a nice friendly aspect of fandom... everyone can participate, no matter what her/his level of talent is. There should also be places, though, that hold you up to some kind of standard, so that you can learn and improve. Actually, I've never before heard of any fan fiction venue, site, zine, whatever, that is concerned with that.
It seems a lot to ask of a fan website, considering that those posting can't move on from there, and make money and careers out of their material, and the editors don't get those rewards either. I'm glad some are willing to do it. If people learn, they can start writing non-fandom stories too, of course.