>(and none of the large merged banks failed while several large banks with only commercial or only investment banking operations did fail)
They didn't fail because the government bailed them out. The government bailed them out because the disruption to society caused by large COMMERCIAL banks failing was intolerable. They needed to be bailed out because they took great risks on the INVESTMENT side. This merger of the investment and commercial side was prohibited by Glass-Steagall. Which brings us around to our initial point: the financial crisis was substantially exacerbated by the repeal of parts of the Glass-Steagall Act, which allowed the risk-taking of the investment banks to imperil commercial banking.
And no, Glass-Steagall doesn't have anything to do with offering interest on checking accounts.