You've put me in mind of something else that is puzzling: the recurring consensus in individual internet fora that their members are really hot. It's a sort of Lake Wobegon Effect for online cliques. (It may or may not go along with constant criticism of out-group members' appearances.) I've found this to be the case in just about every online community I've observed or been a part of, from feminists to law students to general-purpose groups, but it's more prevalent in those that tend be to culturally rebellious. Maybe the same sort of contrarian impulse that makes one embrace bizarre facial hair or the fat acceptance movement somehow blinds people to the fact that they and their friends look, by and large, depressingly average. That's fine: average people are not doomed to a loveless, lonely life. Average-looking people find partners---usually equally average ones. Love makes the average person beautiful in the eyes of his or her significant other, and we don't often find fault with that. However, whether it's the love and bonding of a tight group of friends or something else that's driving this bizarre obsession with overestimating the relative attractiveness of their group, it's damned annoying to those of us who, I don't know, have eyes. They are pasty and doughy from hours at the computer; they are saggy and wrinkled and far outside even the pre-Twiggy beauty ideal; they are scarred and balding and covered with unfortunate tattoos. (It's okay to be those things! It's okay to just be a regular person! We other regular people, the ones with relatively accurate self-images, would appreciate it if you'd come back down to earth!)
Many things can make an average-looking person sexy: personality, sense of humor, intelligence, kindness, etc. But these are not typically what's in play. If someone wants to say that her friends are attractive because they're funny and cool, fine. But don't try to tell me that all your friends just happen to be 10s. If that's true, they've probably been using stolen photos from Russian mail-order bride websites.
* I'm not arguing that beautiful and popular people are better; they are more something, though, and that something is a concept with content. Isn't it perhaps the people who argue, against all external evidence, that their painfully plain pals are actually supermodel-level hotties, who are actually unable to separate merit from appearances? Why does appreciation, or even sexual attraction, for someone have to be so tied to their being physically attractive that we can't see what's in front of us?