It might not be the most logical thing to do, but it's not like it's necessarily an immoral thing to do (as "Let's rephrase your statement: 'Paying back on things you've already purchased...'" implies).

It's one thing if the money is borrowed from a friend or family member (as a charity or with extremely below market interest rates). But the 2.43 trillion dollars of debt that you cite is almost entirely with institutions which make a profit off of debt. [not bashing creditors]