I live pretty close to San Diego, so I think I have a pretty good pulse on the area. In short, no, SD is not a sports town. San Diegans might get around to caring about their team *if* they wake up one morning and realize it's one of the best. Even then, they know next to nothing about sports, and are only as outraged as they are about LT because they feel betrayed that they actually got around to backing a team these last couple years, and it has now let them down for two years running. San Diegans convinced themselves that their teams could play with the big boys, and now they're been repeatedly proven wrong. As soon as LT's decline as a running back becomes more prominent (and running backs near 30 with knee injuries don't have a good track record), they'll all stop caring again.
That said, aside from the sports scene, SoCal pretty much rocks.