I rented in Seattle between 1997 and 2011. Compared to owning the same homes in that time period, and even considering that there was a huge boom (and bust), I saved tens of thousands of dollars.
And of equal importance, when I decided to move to KY, I simply gave 30 days notice. :-)
Oh, there's many out there that demonstrate plenty of mobility regardless of "owning" that house. What's the point of sticking around to complete the sale with no buyers for an underwater unit?