Cost of living, namely rents continue to crawl up (00 for a room in a shared apartment is starting to sound like a good deal).One magazine described the city's economy as "tech and the rest of us".I've been amazed how many people out in bars have the blue smart phone glow on their faces for more time than they actually talk to their friends.
Tech use- Technology does facilitate meet ups and friendships but near non-stop use of it also separates people.
My female friend says "There's tons of dudes, but they're all gay or shorter than me".
I overheard a group of girls walking away from the Elbo Room (Mission) saying "there are two types of guys in that bar, guys with girlfriends and gay guys!
We have more ways to express our individualism than before but now have far less in common with other people because of it. Add ethnicity to this mix and you can get an even more separated group of people.
I know of several ethnicities (many of which are well represented in the bay) that strongly encourage people to date or couple with people of the same ethnicity. Thankfully, there is still a lot of intermingling across cultures and sub-cultures (we're still just humans).
People are into so many different things and scenes here.