San Diego would be a very popular city at lower prices, but simply put there isn't enough population in the US to even think that demand could grow anywhere close to those levels. It would take a 50 year long gold rush, draining of other American cities, etc. The fastest growing city in modern history, Shenzen, grew 6000% in 30 years, and it could only do so because China simultaneously had the highest population growth in the world and the highest urbanization rate in the world.
At some point, demand is saturated, and it takes an extremely delusional belief that demand can perpetually grow so that prices never drop. We have proof in the article that prices can drop with even moderately fast construction rates. Keep going.