Mostly because, in the majority of cases (notable exceptions being the Fannie Mae accounting scandals a-la Enron, for which the respective CEOs responsible were not only not punished or tried in court, but went on to serve as advisors to our soon-to-be inagurated president), what they are doing is not illegal, regardless of how often you call them crooks, felons, and thieves, or how strenuously you wish their activities were illegal. Credit default swaps, derivatives trading, and short selling, regardless of your personal view of the ethics of lending, hedging and speculating, are not illegal activities in and of themselves. Nobody seemed to mind all that terribly much when these same investment vehicles were paying dividends to their 401(k) accounts, or when they were flipping real estate for 150% profit every 2 years. The best punishment for incompetence is the consequences of incompetence. Sans government bailouts, bad financial decisions yield bad financial consequences. Failure and success serve as mechanisms that naturally regulate the market.