Building density housing is cheap compared to building the schools, parks, fire, police stations, and transportation to support the new density housing.
And to close the circle, Prop 13 makes it impossible for towns in California to tax residents enough to pay for the required parks, schools etc. There is an obvious solution (repeal Prop 13, and bump local property taxes enough to cover the infrastructure the new residents will need) but it's politically infeasible.
Are developers expected to build those? Don't cities build roads, schools, parks, and police stations with the tax income from the people who live in the houses?
We've had this problem with developers as well - they want to build mega high-rise apartments with no parking whatsoever and force the city to deal with it, despite the city struggling to fill current transportation demand.
Sure, maybe. Offering to build them for the city is a great way to build goodwill for your project.
If you want to see the ridiculousness of building in the Bay Area, however, you only need to compare this project with another large project proposal somewhere else:
https://chicago.curbed.com/2018/5/11/17340660/the-78-related...
This is nearly the exact same size parcel as the mall in Cupertino. But they are proposing 10,000 housing units and 13 million square feet of development (5x as much). The article calls it "surprisingly low density". But the plans include a new transit station, new roads, many acres of public space, etc. What it will come down to, though, is that the city will say "if you build this, we'll build that". The elementary school that will serve this development is already under construction. So it's likely that the developer will pay for at least half of the train station - it would be significantly more expensive than a school because it is underground at that point.
Btw: The U.S. Department of Housing and Urban Development (HUD) defines "affordable" as housing that costs no more than 30 percent of a household's monthly income.
"WTF is this doing here with all this insanely expensive land and such!?!?!"
I would half expect the bulldozers to show up with 10 minutes notice or something. I was driving around all amazed by "OMG I know all these cool companies!" .... "What the hell...."
Although both pay property taxes and both require utility services like water, sewer, and waste collection, non-residential properties attract both in-town residents and outsiders from other jurisdictions, who then typically spend some money in your town. Meanwhile, residential attracts new residents, who may or may not take jobs in your town, could be spending money in other towns, but need high-cost social services like public schools and community programs in your town.
But previous zoning proposal that were ballot initiatives got defeated (hurray democracy) and it's required a state bill to force the city's hand for zoning. (https://www.mercurynews.com/2018/04/02/community-reacts-to-d...) But still no agreement between the city and the developers.
I'm sure most malls will be trivial to rezone as cities would rather have something paying taxes rather than nothing but that's not the case everywhere.