Reading some of the early comments, it seems like people are acting like this just affects artists or poor black people or that this is somehow a reversal of white flight (largely a middle-class phenomenon).
I grew up in San Francisco and still live in the Bay Area. Middle-class and even many (by national standards) upper-middle class people have been and continue to be pushed out of the city. It's not really about racial diversity either. It's a socio-economic and cultural thing. It's also an age thing. To me the quintessential San Francisco resident is a yuppy transplant female in her late 20s or early 30s . She works in tech marketing. She's a foodie and loves visiting all the trendy new brunch places and maybe hitting up a street fair afterwards. She could be white, Asian, hispanic or something else. That doesn't mean it's not monotonous and homogenous. It is homogenous and that's what people are complaining about. And if you want to have a family in San Francisco, you need to be downright wealthy. So there's nothing wrong with being a young professional in itself, but when that's all a city has it's lost a lot of its character.
Anyway, such is life in a market economy. I don't know if there's a right or wrong here and a city like San Francisco has seen waves of demographic changes. But don't think this is like people complaining if white people were to return to inner-city Detroit. This is nothing like that. This is really an entire city becoming like the wealthier parts of Manhattan. I don't expect people from other cities to care, but as a San Francisco native I wish Silicon Valley had been a place in Washington state.