Over a 30 year term, you're going to be in to 3 water heaters, 4 washers and dryers, a fridge, and a roof (on average). That would be optimistic, as any homeowner will tell you. Other things go wrong.
Small price to pay for 30 years worth of equity. (along with all the usual pitfalls of home ownership) Unless you bought on swampland or the middle of a desert that's gonna add up nicely.
While home ownership isn't for everyone, and renting can have its advantages, personally I'll take owning any day of the week.
It's been my experience many people who've gone underwater were in some way unrealistic to begin with. ("Sure thing! 700k for this 1br/1bth cracker box in the hood is an excellent idea!") A lot of people were caught up (and still are) in the whole stupid "flip it" craze where just slapping on some paint and a new kitchen to sell for $100k profit until the median price of any house was past mere mortal levels of affordability. There always was and always will be a bottom drop out effect to that, and the biggest suckers will get stuck holding the bag.
But again, unless you bought on swampland in a crack hood, I don't really see "losing everything." Even after the idiotic flippers crash the market and people who fell for it go "underwater" once sanity returns most properties will return to a fair market value. (All the smart people will of course buy during the low points of this cycle but I'm talking the average buyer.)
Several people I know who were screaming like banshees a few years ago at being upside down have since kicked back and enjoyed a huge resale profit, or have themselves a nice income property.