Foreclosure...

In today's world we live in we have seen a lot of homes being lost due to foreclosure.  Well not due to that but due to the irresponsible banks that lent money to people that could not afford that payment in the first place, and for the irresponsible homeowner who even thought they could handle that payment.  I totally understand when I person loses ones job, becomes ill, there is a major death in the family and they are forced to step down from there job.  It is the ones that just up and decide one day hmmm I think I should just stop paying on my house, they could save allot of money for months possibly years before the bank forces them out.  Even then there are beautiful rentals now, and contract for deeds that are all over.  Maybe there house value has fallen below what they owe on it and they think well better for them to just wash there hands of it.  In my mind I can't for the life of me figure this thought process out.  Why would someone deliberately do this?  I see this everyday, people out spending money, going on vacations, enjoying restaurants everyday, but they don't have the money to pay for there house payment!!!  UNREAL!