A lot of uber rich actually prefer renting. Short term and high end, renting is usually a lot cheaper than buying, and the money saved will have a higher rate of return in the stock market rather than the housing market.
If this were true, then they wouldn't be buying property all over the world to put their money into as a relatively conservative, safe asset.
The question is, how does Boston figure out a way to find a balance between keeping rents low enough so it doesn't drive out the talented people-particular those young, bright college kids you want to keep here to help build the next tech giants, research and practice the new breakthrough in medicine, be a scholarly academic at one of the area's universities.