I agree with you here, but this doesn't detract from my main original point. All of the things which caused the problem were totally legal at the time they were done. So while side-issues like this are criminal and deserve to be punished, the actual things that caused the problems were completely legal. The Sec investigators couldn't prosecute for melting down the financial system, because it was being done within the law. The law was (and is) wrong, but that doesn't make most people on 'Wall St' criminals.
Among all the things wrong with the financial system, insider trading is arguably the least important. The publicly known conflicts of interests should be alarming all in themselves.