Any one on two wheels is a friend

Ironically, I ignore the polo forum, as to me it is the place where all the most cliquey, backbiting and bitchy aspect of the forum originated (or retreated to):? viz "no polo no talk".

You know I often disagree with you Niall but really....
the polo forum is a model of what the whole forum should be like. It's the exact opposite of what you describe; it's not a clique, anyone who is involved in polo (eg even twerps like me who don't play) is welcome, and there is a distinct lack of backbiting and bitchiness. There's banter and argument but it never really gets unpleasant and people would be called out on it very quickly.
Perhaps it works because it is small, the people involved can't really afford to fall out and so are more willing to reign themselves in, they are bound by mutual self-interest. The no polo-no talk has been successful at keeping the polo forum from degenerating in to too much digression or bullshit. All that phrase is asking is that people show the consideration, respect and common sense they should show anyway.
I doubt very much that the forum as a whole can work the way the polo forum does but it can certainly learn a lot from it.