Regardless, these people are not "natives" who got SF entirely in its current state from God, it was growing up, as prosperous cities do, and neighborhoods were changing. So why should it stop its development in 1976, why are people who moved in to SF back then entitled to this? If you ask me, this is becoming uncannily feudal.
But essentially this basically comes down to gentrification vs preserving culture. Do we value cities as money-making assembly lines where all the workers are replaceable or do we value cities as a living thing, with the culture(s) as their bloodline that makes those cities what they are and gives them their appeal? Do I want to keep my neighborhood as it is, for my children to grow up as I did, or should I just let anyone come and change it, for better or worse?
the letter I used as an example was definitely not from a minority person