Inelastic demand. Even with full throttle development, when you have a whole country (nay, world) of tech industry professionals would want to move to the heart of their industry in a boom time, you may not see much movement in price. Consider that all that worldwide demand would need to be soaked up before prices come down to working class affordable levels. We see inelastic demand with disasters as well as economic booms centered around geographic areas.

You see something similar in the phenomenon of how adding more lanes to roads doesn't necessarily relieve congestion.