the rent is too high because of the market incentives. zoning laws are one of several dynamics that influence the market.

we've built a ton of structures with existing zoning laws when the economy is good, more than we've built during this deregulation paradigm. we stop when the economy or market is bad. very simple concept.

All things being equal, SF has some of the most desirable weather on the planet, so it will always have an high cost of living due to excess demand.