The Department of Treasury is not a profit center, simply because it is not intended to be one. While some of Treasury's financial do make untended profits, which by law go the US's general fund, the role of Treasury is to stabilize the financial systems that key the economy of the country. In addition Treasury is tasked with providing the President with information and advice on financial policy.
Considering the U.S. Treasury is run by the federal government, I do not believe that it really is a profit maker. If it wants a profit, it can simply print money, as it already does for the government to help pay of its debt. I do not believe that it is actually a profit center though.
The Constitutionally defined role of the Department of the Treasury is to promote economic prosperity and to ensure the financial security of the United States government and its citizens. Treasury does this by advising the President on economic and financial issues, operating and maintaining systems that form the nation's financial infrastructure. It does not make, nor is it intended to make a profit from these activities.
No, I do not consider the U.S. Treasury to be a profit center, and instead I think that they are just trying to stay afloat in the financial world. I think that the people who run the Treasury are clueless when it comes to dealing with money, and they are lucky to be functioning.