Then the answer would be...because the American people allow it.
You're blaming poor working stiffs for the corrupt that ran Wall Street, the banks and lending institutions into the ground, as government leadership, in charge of overseeing and regulating these institutions, was directly responsible for driving it into the ground? And you say it's the "American people's" fault?
Ya notice not one single politician, no one government official had the decency to resign over this disaster? Not a one.