Its the culture.
Mortgages used to be part of the slo-mo capitalist culture, as compared with the go-go speculative variety, the kind that looks for the quick kill and run investment. Slo-mo is stodgy, responsible, and dull. Its where the investor goes who wants a solid but modest return on his money. For the slo-mo culture, boring was a positive virtue.
But more and more people got drawn into the casino, because thats where the action is. And mortgages didn’t fit that model, they were sedate and predictable. Perhaps more to the point, the person/bank that made the mortgage was responsible for it.
Once mortgages became “securitized”, bundled together and then sold as securities, they became part of the go-go culture. They became riskier the moment that so many mortgage creators no longer had to stick by their mortgages, they could pass them along. It was free money, they make the mortgage, they sell the mortgage, they take their cut and forget it. You couldn’t create a more likely scenario for chicanery. At first it was just the scoundrels, but when the responsible broker in his BMW saw the scoundrel zip by in his Jaguar, well, all over but the shouting.
The other part is the fact that so much of our housing is geared to the higher-end market, there is more money to be made building a $600,000 house than 4 $150,000 houses. Trouble is, sooner or later you start to run low on upper-middle class people to put in those houses. But hey! if its not your money, you don’t have much problem with “helping” a working class family buy something they can’t afford.
At last, the point when go-go and slow=mo became indistinguishable, when the real estate market was so hot people were buying houses to sell them, just like stocks, make a killing and run for the border. Each time one of those houses sold, the price went up as the cut was taken. Absolutely inevitable that, sooner or later, someone would buy that house for more than it could ever be worth if the next fool does not materialize.
We used to have rules that said that stodgy old bankers couldn’t be go-go, up to the second financial hipsters. This was found to limit creativity and vital, vital entrepreneurship. Well, we got creativity, we got entrepreneurship, then we got boned.