Nobody is against housing development in San Francisco? It is not really a controversial position that it is very difficult to build new housing supply. There have been numerous well studied articles on this fact and a variety of first hand accounts from real estate developers who have had enormous difficulty in building new housing in the bay area.

edit: candidates may run on new housing development as it easy an easy thing to say and run on. But when rubber meets the road, local planning boards and strict zoning requirements mean translate into orders of magnitude less development than people would like or the market would have.

there are both city wide studies and the specific examples like the infamous laundromat or garage-door based house that are deemed too historic or architecturally significant (standards that would not hold up else anywhere in the nation)

for info on the two examples, google "Largent House" or "SF Mission Laundromat redevelopment"