If people like Krugman believe that JPMorgan's one-time loss of $2 billion is unacceptable, why would he propose that the federal government get involved?
The federal government operates their business at a daily loss of $2.5 billion. Everyday. Even weekends.
In the history of the world, there has never been an entity that has better made the case that it is uniquely unqualified to tell any other entity how to run a business than the United States federal government.
True, the NY Times could also make the case for their own organization on a percentage of income to loss basis, but they are going broke on a much smaller scale.