The article's subhead is "The city’s devastating affordability crisis has an unlikely villain—its famed progressive politics."
That needs an adaptation of an old joke: "What's unlikely, Kimo Sabe?"
Related: "How Burrowing Owls Lead To Vomiting Anarchists (Or SF’s Housing Crisis Explained)". It's long and complicated, but part of the explanation is this: ". . . parts of the progressive community do not believe in supply and demand." (Another big part, as usual in articles of this type, is allegedly Howard Jarvis.)
Even worse news for California: it is "so hard to get a great bagel" there.