re: "It should recognized that NASA's job is NOT to make rocket fuel,"
Haliburton, or any other company that is willing and able to invest the capital needed. I don't think the US govt has any right or a good rational to issue a monopoly- but it could be legal offer to buy rocket fuel from an America company and thereby effectively grant a monopoly.
I think an open market is the best approach and wouldn't favor exclusive contracts given by the govt, but perhaps this won't the approach decided on by the political process.