The Debt Ceiling

I do not understand how the U.S. can default on their loans, but if I have a student loan, I am penalized. Does this mean that we, as a country, have failed at Capitalism? We are being bad capitalists right now and the solution seems to be a government shutdown? That is written in the form of a question because this is how I understand it: we print our own currency and the US dollar is not backed by gold. Why can't more money simply be printed? As Americans, we have to undergo credit checks in order to receive employment. Wouldn't it be fair that the US government receives some form of punishment for being financially irresponsible? I also don't understand why the government shutdown merits the amount of media attention it has received because--from what I have heard, it has happened several times before!