Who's to Blame for those sub-prime mortgages?

Yesterday, a New York Times article pointed out that everybody is suing everybody over the collapse of the subprime mortgages and the financial instruments built upon them. They ask, in that case, who's to blame? My suspicion is that an awful lot of the big entities who traded this junk knew what they were getting into, and they could all have used an extra dose of decency. But this stuff is way beyond me. I won't offer you any financial analysis; I'll just tell you a little story that my father liked. I'm afraid it's ... germane.

A man calls another man and says, "I've got a shipment of sardines to sell you. Ten cents a tin."
"Sounds okay," says the other. "I'll buy it."
Shortly afterwards, that fellow calls a friend. "I've got a shipment of sardines to sell you. Eleven cents a tin."
"Sounds good," says his friend. "I'll buy it."
Later, that fellow makes a call ... and right here, we'll make a long story short.
A few days later, the original fellow gets to wondering what happened to his trade. He calls his friend, calls that friend's friend, and so on, until he gets to the guy who bought the shipment for eighteen cents a tin.
"And who did you sell it to?" he asks.
"I'm not selling it. The wife and I LIKE sardines. We're going to eat them. When do they ship?"
"When do they ship? What do you mean? These sardines are only for buying and selling!"

Anyody want to live in a sardine tin?