Your premise is partly incorrect, but even if correct, your implied conclusion is largely wrong.
Home buying in the 2000’s and stock buying in the 1990’s were touted very widely, with magazines, newspapers, bankers, brokers, etc. all united in preaching the message that prices would never fall. People reluctant to buy expensive houses were coaxed into it by brokers. Many of these commentators and brokers were themselves gulled by the bubble’s illusions, but not all. One of the highest rated supply-side analysts on Wall St. became famous for strongly recommending stocks publicly that he was calling “dogs” in e-mails to preferred customers. (I still don’t understand why he wasn’t sent to prison.) Perhaps a large majority of brokers and commentators were as “nuts” as most of the rest of us, but it would be naive to disbelieve that at the very top of the financial food chain, bankers were well aware bubbles burst and were laughing privately at the fortunes snookered from the gullible.
So the premise that the common man fell victim to his own greed is incomplete. He had a lot of help; naive homebuyers were strongly urged to buy homes more expensive than they’d intended.
But even if your premise were correct, the conclusion is wrong. 49% of the people are below average in intelligence. To blame such average people for being victimized by con men is inhumane. It is precisely because people are imperfect, and because average people are not expected to take a college class in Bubbles and Burstings that regulation is needed.