I'm at a tailgate, a curious friend of mine reveals that he was trying to learn Ruby. I ask a couple very _basic_ questions, and I get looks of "not here".
Anything too technical comes across as exclusionary. The nice thing about SF is that every third person you run into is an engineer, so you never have that social problem. In fact, you have the opposite problem of always defaulting to "talking shop" with someone new.
I think what got me the most was a dearth of jobs outside finance & Content Management Systems.
I worked out of Columbus for a week and REALLY loved it, but getting up before sunrise to get in a morning run while it was 'only' 75f and 127% humidity was a real downer. I think I could stomach the winters more than the summers.