Sometimes, it's not about a "quick killing" in the market. I walked away from a house in Massachusetts in 1994. The house wasn't particularly overpriced, and the mortgage was reasonable. But the Mass miracle (remember Dukakis?) went bust right after I bought the home. Got laid off from one job and commuted 3 hours a day for 3 years to keep the house. Got laid off from THAT job, and the only thing I could get was an even longer commute. Couldn't sell the house because the nearby Army base had closed in 1991 (thank you GHWBush) so housing prices were depressed. Took a long time to get over losing that house. Took years before I could buy another one.

Things do change in people's lives and with a housing market that wildly and widely swings from overheated to depressed it is difficult for anyone to get into or out of the game without financial damage all around.