Sure, if you're 100% sure you will never move, you can ignore the financial aspect. But people do move, for many reasons. If you owe more than your house is wor

Sure, if you're 100% sure you will never move, you can ignore the financial aspect. But people do move, for many reasons. If you owe more than your house is worth, now you're trapped. Hard to ignore. I assume this is one reason we have zoning rules -- so you know what your neighborhood will look like in 10-20 years. Important with a 30 year mortgage. (If your point was those with 2nd homes or investment properties that they don't live in -- that's an issue. See Vancouver, and various Bay Area cities.) Edit: by "investment", you might mean someone seeking an appreciation of $500k vs $300k. I was thinking of $0k vs losing $200k. It happens.