Penguin, have to agree with you too.. and appreciate the fact that not only were borrowers irresponsible, but also lenders were as well.
In many respects the lenders were also borrowers. However the 'Lenders' that were also 'borrowers' have risk analysts who determine the risks over what they are lending and what they are borrowing to lend.
In many cases the risk analysts were flatly ignored as the downside did not fit into continued bubble projections.