And that is the paradox. In order to make cheap housing you'd have to destroy all the open space and low density zoning that made all the tech and VC people want to live here in the first place. Besides the current economy isn't permanent at all. The tech bubble will bust and this will all go back to normal in a few years. People who are living here for the long haul, and not just for the gold rush don't want it to get overbuilt and spoiled. The funny thing about the bay area is that people are not really impressed by the economic benefits of further development because collectively people have an enormous amount of money in the wealthier bay area cities and no amount of money being waved in their faces will make them give up their quality of life.