In a lot of ways San Francisco is one of the best cities, but in other ways it becomes the worst. (Though I think anyone who would be happy in Decatur Ill. - and I have been there, or at least passed through a few times - would not like SF, or LA, or any large city).
It's pretty hard for people who come from a heterogeneous area and culture to adapt. I often joke when I met someone who just moved out here that I really don't even want to talk to them for 6 months to a year, just because I don't want to spend that time explaining stuff. Lets just say that it can be a radical readjustment for many, and not all like it.
Being a place where lots and lots of people want to live (and for all sorts of reasons beyond Trans), it's expensive and highly competitive. In highly competitive places you tend to be thriving or sinking fast, I think it's true about most big places, its just that SF is 49 square miles, so it's a lot more apparent - at any rate, if you are making marginal money, then you will have to live in a marginal area, and that's with junkies and other bottom feeders and dwellers.
If you have no real job skills, no outstanding educational background, and 'have trouble' with many social interactions I'm pretty sure this is the last place you should be.
People celebrate diversity, which makes it good for some of the odder people in the universe, but in a lot of ways 'diversity' amounts to a lot of apathy too, and some find that hard to take. And, though I know lots of people seem to think they would want an environment where, in general, people don't care about how you live your live, there is a level of callous brutality when you come to find out that the reason no one cares about how you live your life is that they don't care about your live at all.
