I cringe myself whenever I hear the abominable word uttered, but... why? Yes, I know about Emperor Norton's edict, but come on. No one really took what else he said seriously. I've also read that everyone used the word back in Norton's days, visitor and local alike.
And let's face it: "San Francisco" is a mouthful. Sure, you can call it, "The City," if you're comparing it to elsewhere in the area, but it smacks of pretension and is downright laughable to a New Yorker. "SF" is fine in writing (as long as the context is enough to prevent confusion with science fiction) but never really caught on when talking. So really, WTF?