[throwaway76543]

This is utter nonsense. There's no evidence that neighborhoods made up of renters are any more or less "cultural" than neighborhoods made up of, well, you haven't really articulated an alternative have you? Do you expect everyone to purchase a home, and not have renting at all?

Generally areas regarded as having a vibrant culture also correlate with high percentages of renters -- because they're in cities. Areas with high percentages of homeowners and low percentages of renters tend to be suburbs.

In any event we can answer your question of what happens when the boom is over because we've already lived through two tech booms in this area. The answer is: Prices fall and folks with investment properties will lose some money but not much else changes. Homeowners get hurt a lot more than renters when bubbles pop.