The word is that BofA did in fact consider declaring their Countrywide subsidiary bankrupt to ring fence the rest of the company from Countrywide. It got as far as a board vote this past summer. The vote failed because the CEO, Brian Moynihan, felt that the move would not end the legal problems besetting BofA as it still has its own problems and ones picked up via the Merrill lynch acquisition. Moynihan is in a position to know as he has a law degree, practiced corporate law and served from December 2008 to January 2009, Moynihan served as general counsel for Bank of America.
This Wall Street Journal video discusses the issues of why it has postponed the bankruptcy filing. That Bank of America was so concerned about its legal problems should tell you that this is a firm with serious problems. In a recession, those problems would increase.