What's the deal with San Fran people?

Why are they so quick to tell everyone just how tolerant, diverse, open-minded, forward-thinking, and intelligent they are? I've met tons of people from the Bay Area that say exactly the same thing about how tolerant EVERYONE is and how wonderful it is to be in an open-minded place, unlike the rest of America. Is tolerance really defined by whether or not people enjoy seeing a dominatrix a man in less chaps on a Tuesday afternoon in downtown San Fran? And of the city is so diverse, why does it seem like everyone you run into in the city is either ual, asian, or an abortion doctor? Are there any black people at all in SF? Any straight people with children? It seems like people from SF constantly talk about tolerance and diversity to reure themselves that this is really true. Any truth to that theory? And, why does it seem like 95% of people in SF believe they are part of some sort of revolution? What's up with that?