When people are wearing clothes that is not seen as a common factor that produces common ground, fellow feeling. You never hear, "hey, your politics stink but you wear clothes like I do so you can't be all bad". Get some naked people together and straight away there is a commonality that sets us apart from everyone else and sets us together, so even if we subsequently discover our politics (or preferred music, or whatever) is at odds we already have that meeting point, that shared "outsider-ness" of preferring life naked. Sure, it's not perfect and it doesn't work all the time for everyone, but it changes the starting point of the relationship, sets in place a different sort of dynamic.
Of course that's at the individual level. Group-think changes the boundaries. "Our group meets on beaches - that's the place to be naked. Their group meets at camp grounds, that's all wrong!"
At the end of the day we're all just people, and subject to the same strains and prejudices and issues as anyone else, so the divisions JBee lists are bound to occur, but (perhaps it's wishful thinking) I reckon we have a common - naked - philosophy which can go at least some way to overcoming the worst problems.