With all due respect, San Diego is boring relative to the Bay Area imho. I've lived in both places, and frankly if you're young and or a very young couple with a lot of motivation, you have to live in the Bay Area at least to try it out.
Things move very quickly up there. You want to go to geekville, head on down south to silicon valley. You want your culture and sheshe lifestyle, head on over to SF. Want to get fine wine, head on up to Napa Valley. Sports: obviously there's the 49ers and err the Raiders (uh, ok not good there). Hockey: sharks (which won't ever make it to the playoffs). And basketball, golden state warriors. (also a dead team). There's even arena football (entertaining). I'm sure there's plenty more to do in east bay, but never hung out there. Berkeley is interesting in it's own, extremely liberal. (san diego, relatively speaking, is conservative and sort of more "whitish"- nothing wrong with it, just my observation). My relative, for instance, went to UC Berkeley, and let's just say for awhile my we were sort of worried about her viewpoint while she was there…We'll at least until said relative ended up on wall street and ended up being ultra-conservative. Still lives up in SF around banker hill, and loves it. And yes, said relative, is one of those folks that would "die" if she had to live in the suburbs.
The only real issue I see with the Bay Area is it's an expensive place to live to achieve the same quality of life as you could down here, though I think there's definitely more opportunity up there. Not a big deal if you're kid has a profession that can sustain it. Ever since I moved here, I've been wanting to move back.
imho, there's nothing wrong with your kid wanting to live in an area, as he/she is entitled to his/her opinion….well, provided he/she doesn't call you back few months later after she starts working and needs money from you. Just make sure she's not a Raider fan that loves to riot when they win or riot when they lose.