Earlier quoted context omitted.
Why everyone needs to be able to afford the housing? Down here in Europe we have about 30% homeownership rate and nobody says we are in a crisis, in fact, we are doing very well. U.S. is again near top of the world in homeownership rate. You are making things up - trying to see a problem where there isn't. Better think about fixing childcare, and healthcare - that's where the real crisis is.
Yes they could just live on the street. By "afford housing" I don't mean just buying, but also renting. Rent prices reflect sale prices.
No fiscal solution could fix San Francisco housing prices, only 'fix' would be crushing Silicon Valley so it ceases to be attractive place to be.
If renting is a problem you are doing something wrong. Median gross rent in U.S. is $959 a month. That doesn't sound much for developed country to me. Buying real estate is accessible to majority of U.S. households, in fact almost every dual income household. 63.7% have it, and many who don't have it, just don't want it (for example, i am making what it takes to buy an apartment i am living in, in 8-9 months, but i am not buying because i am not a gambler). To me not buying real estate seems a rational choice, unless you have a very 'fixed' career - like, certain that you are going to stay in a place for decades. There are fewer and fewer people like that, labor market gets a lot more fluid.