In a city like San Francisco, relative to the status quo ante easier development is more likely to result in slower growth in home prices, not a reduction in home prices.

But that's not the reason most San Franciscans oppose development. The primary reasons are 1) they're convinced more development will raise prices, 2) they believe affordability must be mandated through price controls or subsidies (e.g. developers dedicating X% of units for below market prices), 3) they insist on bike shedding every development proposal to death, 4) they're convinced private development is inherently inequitable (only "luxury" housing is built).

Pretty much the only group of people in the city worried about housing stock increases reducing prices are developers trying to sell-off new units. But developers are repeat players, and they're generally not the ones lending support to development hurdles. Though, there is (was?) at least one long-time developer who specializes in building "affordable" housing--mostly at public expense, of course--who did aggressively lobby for development hurdles, but carefully crafted so he and only he could easily get around them.

> It's harder than you think to argue for a house price decrease when it's the singular asset that most older adults have most of their wealth tied up in.

The only thing they can exchange it for is another house or an alternate form of housing. Because you have to live somewhere.

But what I have seen is worries about social class and sharing space with new neighbors who act like they're from the next rung down on the ladder. Which isn't all that different from the usual objection to short-term rentals.