I worked in the financial industry. I wasn't a banker but I worked with bankers, and I understood banking. I think it's possible that no bankers went to jail because what they did wasn't actually illegal. It was immoral; no question. But in order to jail somebody, there has to be a law against what they did; and you have to be able to pin the violation on them.
Most of the financial meltdown happened because of a bunch of financial tricks and ploys, mostly called derivatives, which were invented over the preceding decade or so. Some of those tricks and ploys were explicitly not covered by the securities laws - because the finance industry's men in Congress had written the laws to exclude them from regulation. I refer you to the late Phil Gramm of Texas; a summary of his career is in this article in from the NY Times in 2008.
Further, most of the men we'd all like to see in jail are senior executives. Believe me, the way big banks operate, the men in the executive office can legitimately claim that they didn't know what the guys on the trading floor, or the loan platform, were doing. So there weren't any laws; and if there were, you couldn't pin them on the men who set the general policy that allowed the actions.
So quit blaming Obama because nobody went to jail.
Postscript: if you're interested in derivatives, you can Google them; or you can look at the blog entries I posted, back in the day, under the tag Subprime Mortgages. I wrote them up while I was watching my 401K dwindle (it came back, thank God).
For that matter, I've said all this before; see my post Finally the Truth, from October 2011.