This Finance 101 perspective is too clever by half.

Sounds like a great idea, right? But what if something out of your control[1] happens, and average interest rates on the debt burden go up from 2% to 14%? The USA can't afford to just pay off all of its debts. It must continuallly roll over it's old debts to new debts, and could easily find itself in a situation where debt servicing costs go up by an order of magnitude if the fiscal situation changes for long enough.

[1] Or in the case of the United States, you do something very stupid and very inside of your control