You have missed an important point. Those loan officers were paid a fee for the service and their institution sold off the loans that were derivatized. The patsy was down the line. They all got paid...
Go back and review the news that came out. "The Big Short" is a decent summary. The trading manager at Bear Stearns who bought the derivatives got to walk out and keep his big bonuses. The share holders ate it. The rating institutions were complicit too - they knew the products were crap but knew the customers (lending institutions) would go to another one and so wrote the bogus ratings. See the players in the game got paid. The snooks got screwed.
Bill Black, who prosecuted the Savings and Loan Crisis, and sent many fraudsters to jail reviewed the 2008 crash and was incensed at the lack of prosecution.
The consumers saw what they wanted to see. Very few consumers perfomed due diligence. The old proverb tends to be true: "If something seens to be too good to be true... It probably is." Fraudsters have taken advantage of the gullible throughout human history. Our generation has no excuse: we have unparalleled access to information and most are too lazy to put the effort in to check these things out our to hire competent counsel who work for us not the seller. How many parents and students understand the debt they take on for college and the expected ROI???