Aside from selfishly wanting room for more local colleagues at my startup, it's my mission in life to preserve California as a refuge for persecuted LGBT people across the country. The best way to do that is to build more housing and stabilize rents, not to block sorely-needed high-density housing because there used be a historic gay bar there 50 years ago that few will remember.
Consequently, I believe that many renters simply aren't participating in the political process or are strangely voting against their obvious interests.
The YIMBY platform will work because the majority of people will benefit from it, but need organization to actually get to the polling booths and participate in lobbying.