Whether it is preferable or not depends on the opportunity cost of the government's capital....
...at least an an ideal, rational world. But in reality the far more important considerations are votes, politics, and lately populism. And if you ask Gen. Clark,
national security.

GM has a lot of issues. However I do sympathize with the bailout side - there are a ton of pension plans, etc. out there that hold GM debt and if the US govt lets GM go then they'll just be faced with another gigantic trickle down problem.
Reforming GM will take someone with a lot of energy, balls, and immunity from lobbyists and government / union interference. But it is necessary.
EDIT: Chrysler on the other hand should just burn.