Amazing, a path opening for a west coast city to develop additional housing! We need more of this. I bet there are NIMBY heads exploding in San Diego, probably on Nextdoor.
In addition, downtown San Diego isn't really considered to be a place where the cool kids hang out (and still has a lot of industrial area around). So, there is less fighting going on there right now.
The problem is that the transit in San Diego is lousy. The trains are horrifically slow between downtown and Solana Beach. And the limited number of tracks means that Amtrak regularly has to wait for passenger trains, and, if someone jumps in front of a train, the system shuts down for 4 hours.
Nearby construction can decrease your property values, but upzoning and by-right permitting increase property values by making them more attractive to developers.
I think it's both more correct and more charitable to think that people arguing against things like SB50 are doing it because they don't want the density in their neighbourhoods, and not for financial reasons.
However, San Diego already has a huge traffic problem. Either they really need to scale the major highways, or get people closer to their workplace, which this is a great first step for. San Diego is awesome, but growing pains showing.