Too big to fail? Dubious, but ok.
Too big to jail? No. Throw a CEO behind bars and the finance industry keeps on going but it scares the shit out of others who would misbehave.
Banks didn't deceptively mix mortgages (which isn't fraud, anyway) and sell them to unassuming buyers. They constructed portfolios of mortgages (assuredly some good, some bad), a third-party rated those new financial instruments as AAA without fully accounting for risks, and sophisticated buyers purchased those instruments, also without fully understanding the risks.
If anything, the blame should be on the pension funds and large institutions who purchased these things and who pay people large salaries to manage this money. But I have a hard time seeing fraud in this process.
I mean, you can read this in The Big Short. Characters like Michael Burry read the prospectus' for these securities and could see what was in them, thought much of it was crap, and made their investment decisions based on that. Anyone who purchased the instruments had the same opportunity, and in the case of pension funds the obligation to do so.
i’m not saying “let it collapse”: a government has a duty to protect its own citizens of course. but i do think the myopic view which subsidizes a system once it becomes too big to fail runs counter to long-term prosperity by making the local optima more trapping than they would otherwise be.