Capitalism needs to be protected from itself. Greed is good, except unchecked it leads to price fixing, pollution, fraud and other ills that have been criminalized, rightly.
Because there was an extended run up in the value of certain markets leading into the financial crisis of 2009, especially housing, the rewards earned by money managers on Wall Street and the risks they ran with other people's money were uncoupled.
Sub-prime mortgages are as good as gold (better!), as long as real estate prices are rising. Universal home ownership, more that universal health care, is a sacred cow in Washington. The authorities were conflicted about blowing the whistle on financial gimmicks that helped put the American Dream in reach of EVERYONE. So they didn't until the financial markets started to melt down.
Changing the structure of financial regulation is likely to be a torturous process, which the people on Wall Street will spend liberally to try and subvert. There is no reason to believe that the end result will effective in preventing future crises. Money moves a lot faster than the regulators do, and structural changes are likely to open new "loopholes" even as it closes old ones.
My hopes for financial reform rest with the old sentiment, "Throw the bums in jail!" What we need is a tough prosecutor who wants to make a name for himself, (Andrew Cuomo?) to go after the titans of Wall Street and make them do the perp walk. (It worked for Rudy Giuliani.)
Martha Stewart, Ivan Boesky, Michael Milkin, et al. - even Bernie Madoff - were brought to justice for much lesser crimes than the crime(?) of ruining the lives of millions of people (the poor, the sick, the old, etc.) around world. Retribution is not a virtue, but it might help deter future crises. And that is why the best reform would be to prosecute the investment firms and throw the principals in jail.