I think you're missing part of the point - are the people moving into SF buying houses/condos or are they renting? I think the point of the article was that housing prices are so high that people can't buy, thus it's going to become a city of renters where properties are only owned by the very wealthy. From a city culture standpoint, I think we would all be in agreement that a city where people own their own homes results in a better environment (more people would be politically active within their district, kids go from K-12 at the same school district thus grow up with a stronger sense of community, etc). I also think we would be in agreement that it's a stronger country when the citizens can afford to buy their own homes rather than rent them from the 0.0005% who can afford to own in SF.