There has been considerable chatter on this message board about people walking away from their homes, stopped paying on their mortgage even when they can afford the payments, etc.
Several here have voiced their opinion that it's not right, morally, ethically, for a homeowner to do that.
At the end of the day, it's business. No different than a bank choosing not to actually foreclose on a property (article was posted on here recently) as they'll have to spend too much $$, or a business closing it's doors, laying off it's workers, not paying any of it's outstanding bills.
Provided the homeowner isn't breaking any laws, they have to protect their best interest. In the same way any business does the same thing.