See my comment above, but the economics of increasing supply are actually much more nuanced, and the majority of current owners would probably not see the value of their assets eroded.
I think this is the best point to shout out, in the Bay Area. Show how building projects can alleviate supply concerns for demographics who can't afford your suburban home, and how the increase in population will still help your home price because it will make your fat suburban land parcel look even more exclusive. Everybody wins something.