SF homeowners of course believe in the kind of property rights you're talking about, but mostly do not believe in the latter. Most homeowners here want (and unfortunately mostly have) absolute veto right over any kind of construction or development that their neighbors want to engage in, whether it's as simple as reasonable cosmetic changes by a resident homeowner, or as complex as a denser rebuild by a housing developer.
(But I mostly agree with you in your characterization of the two types of SF homeowners. There also are some who are nominally in your second category but wouldn't be catastrophically financially impacted if their mortgages went under water, but they're definitely in the minority.)
If they care so much about property rights then why is it so hard for people there to do build on their own property that increase the value of that property?
Saying SF cares about property rights is like when the person who creates drama says they don't like drama.
There are two types of people in SF:
* People who have watched their property appreciate in value by 4-10x for basically doing... nothing.
* People who have taken out an eye watering loan for well over a million dollars and are kept up at night by the idea that theyll owe a million dollar loan on a $750,000 home.
Of course they're going to be conservative! Of course they're going to try to avoid anybody rocking the boat! Of course they'll be NIMBYs!
Why on earth would you think that the one thing that keeps them ludicrously wealthy - property rights - is the thing that they'd stop believing in??
It makes zero sense.