Not necessarily. Keep in mind, property/land-owners own, as you mentioned, the land beneath their house. That land might be worth far more if it were rezoned

Not necessarily. Keep in mind, property/land-owners own, as you mentioned, the land beneath their house. That land might be worth far more if it were rezoned for multi unit dwellings. Property owners in SF are often opposed to new construction, but I don't think that they are motivated by the desire to maximize the dollar value of their real estate assets. They're happy with where they live, they often bought long ago so their costs and taxes are low, and they just don't want change, especially in medium density neighborhoods that have been stable for 75+ years. Their opposition to rezoning probably goes against their economic interests measured purely in dollar signs. People in rent controlled apartments have a similar motivation. Their costs are very low, they don't want the disruption of new construction, and they are often concerned that there wouldn't be a place in the new construction for them. Why take that risk? The difference is that people in rent controlled units are more vulnerable than property owners. If they do find themselves out of a rent controlled apartment and on the general market, competing for the few new units that become available, they'll be displaced.