San Francisco, Sacramento, and even Chicago have successful Soft ACs. And none of them are retirement havens. KBEB skews more heavily towards softer tracks compared to, say, WDUV, which is interesting, considering that Sacramento skews a little younger. And KISQ does pretty well among 18-34 and 25-54 whilst being pretty mellow.The older the music = the older the audience, which means harder to sell. The reason why soft AC hasn't grown is because the format is hard to sell. Audacy may get a smaller audience with alternative, but it's younger than it would get with soft AC.
Anyways, back to San Diego. Wouldn't a growing non-white population (yes, it's growing) make alternative radio less viable? And I'm not sure if non-post grunge Alternative does well among a more conservative military audience. Even Boston and Providence, which both have a high concentration of liberal whites, lack commercial alternative radio.