It's very understandable once you get into the nitty gritty economics of it, where there is no tax on unoccupied housing. F there were a substantial tax on homes that were empty, that would incentivize landlords to rent out housing instead of having it sit empty.
It would crash the economy though. Apartments are valued in terms of asking rent hence being content to eat at some rent earning potential to maintain value of an otherwise appreciating asset. Many people are leveraged in this real estate market by virtue of buying wide index funds which contain companies in this industry, either directly or in their retirement package.
