I think 2 things here: people today seem much more likely to relocate due to work and other preferences...in 2018 the median duration of holding a personal property is 13 years, hardly a lifetime. But lets say that someone buys a house and owns it for a lifetime...eventually that will be passed down to the kids or whomever, and they may want to liquidate in order to move somewhere else. Although in 2008 and also today much of what was/is happening in complete speculation, which upends the market for many people.