Despite conventional wisdom and lots of hand-waving justifications, there's actually very little evidence that building more luxury units impacts low-end housing prices on anything but the long term. Even the author of this piece is falling back to long-term averages to make his argument, and the results are...tepid. A 2% reduction in aggregate, long-term rents for every 1% of new housing built is not a screaming endorsement for indiscriminate construction.
If you have data that shows otherwise, feel free to cite it.
No part of this market in any way resembles the market for Lamborghinis and Kias.
The question is whether or not new luxury housing makes rents cheaper for poor folks, today. Even here, in the epicenter of a housing crisis, there's not a lot of evidence that it does. But there's evidence that preferentially building low-income housing does make a difference.
This isn't a controversial or irrational or counter-intuitive argument: there are a lot of great reasons that a rich person might choose to live in a cheaper apartment. It isn't a given that rich people will self-segregate to luxury buildings because "luxury". So at the end of the day, you're back to aggregate supply vs. aggregate demand. And if that's the case, why not build for low-income people instead?
(I lived in Bayview for a bit, and I was hardly the only tech person I knew who lived there.)
I'm not claiming that they do. I'm arguing the opposite: if you build only luxury, it doesn't help poor people much, because most people will try to get the cheapest, nicest housing they can find. Building luxury units helps only to the extent that building anything here helps -- and if we believe the OP, it doesn't help very much at all.
Basically, this: you lived in Bayview, so you know who lives there. Knocking down every existing low-density home in Bayview and replacing it with market-rate housing would displace a huge number of poor folks. It probably also helps lower aggregate rents for everyone in SF by $40 a month or whatever, but that's thin gruel to the people who were there before.
This is the fundamental dilemma facing all construction in San Francisco.
There's no guarantee that building luxury housing lowers prices, which is what you were implying. You have to take it on a case-by-case basis.
The price of Lamborghinis doesn't have much to do with the price of Kias.