I had an insight into why bankruptcy is so difficult in the US, sparked by my friend Vincent. He pointed out that a big sticking point was that the Republicans insisted the bailout strip away many of the benefits enjoyed by the GM and Chrysler workforce. The automakers' union wouldn't agree to all the concessions, and the Republican senators wouldn't vote for the bailout unless they did.
Hostility to government means that big companies in the US take on responsibilities that fall on governments in other developed countries, particularly health care and pensions. Elsewhere these benefits aren't tied to the health of a particular corporation, so its failure is less devastating. The current workers have to find another job and might lose the pay for their last week or two of work, but they still have health care and their accrued retirement funds (the latter might be diminished by poor investment returns, but don't disappear along with one particular firm). Conversely, a bankruptcy in the US leads to workers losing benefits accrued over decades. This injustice creates a strong political constituency for propping up a dysfunctional company, even when society as a whole would be better off if it failed and made way for a superior competitor.
It's an exquisite irony: the failure to put in place socialism for individuals leads to socialism for corporations.