I was complaining to a friend recently about how the city of Mountain View has approved so much new commercial property development while approving very little residential property development. And he brought up a good point. A lot of the unused space in Mountain View is superfund sites. The development of new commercial space is happening at these sites (the whole area around Moffett including Google). It's easy to ensure commercial entities are meeting the requirements to mitigate the pollutants in these areas (proper HVAC and ventilation systems, etc) than with individual residences - and the limits on the amount of exposure are also lower for commercial areas vs. residential areas. So this could be a strong factor on why there's way more commercial development than residential in Mountain View and surrounding communities.