SF is not the world. The POV is of SF city only.
SF also does actually sit right on top of a fault line, so it is not a staid place by any stretch of the mind. It was just over 100 years ago the entire place burnt to the ground and was rebuilt by greedy logger barons (Cowell, Lick, etc.). It is a matter of time before another bad quake happens again, though maybe to Market as badly the next time. I agree they want the amenities, but SF is a port and it needs its vices, despite all calls to the contrary. People that need the amenities move to Napa or Dublin. Also, SF has never had real problems with flooding like St. Louis does (see: the hills) or the bad air like on Mexico City or LA (see: the bay fog rolling in).
I've no idea what drives the romanticism when you can smell the streets even in the rain. Then again, the French are like that and their streets are covered in doggy land-mines like SF's are.