[epistasis]

Is there a 120 unit condo building in SF that's being held off the market? Has a person lied to the census taker that's it's not housing? These seem like important accusations and if true I'd be as upset as you are, but I certainly haven't seen that.

As for commercial space that's not housing, that's up to the city government to change, and the city government and resients who show up to planning meetings oppose that sort of rezoning. This being a conscious action of owners of industrial and commercial property. Are commercial sites more valuable than residential right now in SF? What sort of use brings these owners more gain than renting our properties that they are legally allowed to rent?

Remember the Ghost Ship fire? The proprietors were charged with involuntary manslaughter for using a warehouse as housing:

https://en.m.wikipedia.org/wiki/2016_Oakland_warehouse_fire

I guess I'm just very confused about what you consider to be very obvious. I can't see evidence of people hoarding buildings that could be used for housing. I do see SF residents preventing more buildings being used for housing, and preventing the building of more housing on infill sites.