An important difference between Swedish and American housing loans

Isn't it strange that the rules for banks and loans varies so much between different countries?

If you take a housing loan in Sweden, you have to pay it back whatever happens. Even if you sell your house to a lower price than the amount of loans, you still have to pay the loan. The Swedish banks don't take any risk in this case.

I've read that in the US, the owner of the house can just hand in the keys to their bank when they get problems, and they basically get rid of the problem. They don't have a house any longer, but on the other hand, they don't have any loans either.
That principal and all the hidden gambling around it (like sharing the risk etc), seems to have been one of the reasons for the start of the latest financial crisis.

The backside of the Swedish rule, apart from all the problems people may get if they have to sell their house in an unfavorable situation, is the behavior of the banks. The banks are happy to give people loans these days, to buy houses and apartments to very high prices, since they don't take much of a risk. Since the interest rate is extremely low, the prices are increasing dramatically when people believe they can afford to take large loans. The risk is now that the Swedish house market is just another bubble. Another disadvantage is that the Swedish banks rather give loans to private persons than to companies. Companies can go bankruptcy these days, but private persons cannot.