You know why? Because ARM (adjustable rate) mortgages are RISKY. Regular mortgages, are FIXED, you pay the market price for them. The rate does change, but it's secure, if you can afford then, then you can afford it as long as you make money.
If you LOSE YOUR JOB. You file for BANKRUPTCY. Guess what. You get to keep your house. That's why it's called 'protection.' It is more expensive for a bank to repossess a house than it is for them to work it out in most cases.
The recent problem was caused by having A LOT of money sunk into high risk debtors. People with ARM mortgages who couldnt afford them once the rates go up. So then you have no choice but to foreclose and then it snowballs and banks start bleeding money and so on.
Bottom line. If you are greedy and get a Balloon or ARM mortgage you are setting yourself up for failure because interest rates do double. If they didnt, I couldnt get new computer parts by cashing bonds kek.