So the government passes laws to limit housing stock, then passes laws to artificially keep rent low, then people complain about prices going up and a lack of housing stock? Has anyone in SF read an Economics 101 textbook?
I'm sure they understand that, but they understand 'elections' and their constituencies even better.
Allowing building upwards would be seen as 'pandering' to 'special interests' by lots of locals --specially people who like to call themselves Xth-generation Franciscan.
SF is always about the short-term but made to look long-term so as to seem forward looking and progressive. The only thing SF is progressive about two things, sex, and some minority causes (both of which are good things but hardly encompassing of the term 'progressive'.)