The people who currently live in neighborhoods full of $5M single-family houses may value “exclusivity”, but I have met plenty of young people with ordinary jobs sleeping in bunk beds, 4 adults to a 2-bedroom house and still paying most of their paychecks to rent, who would much prefer to be living in separate 1–2 bedroom flats instead, with more little shops in their neighborhood and better transit.

Sure but they could move almost literally anywhere else.

If someone said you could live in one of the most desirable places in the entire world on an 'ordinary' job but you had to share a room (which TBH could just be your significant other anyway) that would seem like a great deal right?

A city cannot function without sanitation workers, plumbers, carpenters, electricians, house painters, road maintenance workers, teachers, librarians, gardeners, bus drivers, janitors, delivery drivers, taxi drivers, shop clerks, wholesale merchants, mechanics, cooks, firefighters, paramedics, accountants, bank tellers, municipal bureaucrats, musicians, bartenders, ...

When many categories of essential workers start to be priced out of living locally and need to commute long distances from undesirable far-flung suburbs, it is (a) a grossly inefficient use of resources, and (b) makes the city much less pleasant and effective. A city where all of the residents are wealthy professionals with other workers as second-class commuters is not a very nice place to live, more like a theme park or resort hotel than a real city.

True. Ideally we would have road tolls and congestion pricing to prevent this. With sufficient tolls, something else would have to give whether that's wages or housing.

No, living with partner is not the same as living with roomate and 3 flatmates. The two are actually massively different.

I'm not saying they are the same or always the case. I'm just saying that is someone is already going to live with a partner, then it isn't a big deal to share a house with another couple.

i.e There is pressure for people living in that area or moving into that area to find a SO or something similar.

And then those adults will either leave SF or climb the ladder and afford to buy a place, then many won’t advocate to devalue what they just worked so hard for.

I own property in downtown SF and I want it to expand massively. The current system is completely untenable. This is not to my direct/immediate benefit of course, the current situation is just straight-up SF city mismanagement.

The people who value the “exclusivity” of the Bay Area tend to be a very narrow demographic. Nothing wrong with that, but it’s not a particular representative group.

I agree that it is a narrow group, but unfortunately it is a very powerful narrow group that controls local politics and has enacted these exclusionary policies. The Calvin Welch school of thought in SF is a prime example.

I'm one of them.