Why is SF so opposed to building up? Build more high rises filled with apartments and condos, there are plenty of areas that could be rezoned to accommodate high rise living.
There's no shortage of housing in San Francisco, only a shortage of affordable housing.
[1] http://paragon-re.com/San_Francisco_Housing_Development_Repo...
And developers don't tend to want affordable housing. That's why it usually has to be enforced by regulations of some sort. They're quite cheap and want to maximize their profit (like any other business). City, cultural, etc concerns come second.
If you placed sever restrictions on car production you'd find the surviving brands would be the luxury brands.
"Due to the capital cost ($1.578 billion for the 1.7 mile light rail line), the Central Subway project has come under criticism from transit activists for what they consider to be poor cost-effectiveness.[20]
In particular, they note that Muni's own estimates[21] show that the project would increase Muni ridership by less than 1% and yet by 2030 be adding $15.2 million a year to Muni's annual operating deficit."