For the most part I'd not see the GFC as a morality tale but rather a kind of weird emergent phenomena whereby one area of the economy became so big and complex that it was beyond's anyone's ability to manage, and the interactions of the millions of bit players in it - all of whom in their own way wanted to succeed and do well for themselves - led to this collectively disastrous outcome.
Which isn't to say that nothing illegal occurred - I'm not sure how you'd draw a boundary around the GFC but there were a number of securities fraud prosecutions in the years afterwards - but I think if you take the GFC and subtract all illegal behaviour, you'd still have the GFC.