The whole system is absurd. I owe these bank some money and even if I had to go out of this country without paying them, I wouldn't feel guilty(but I won't as I can pay them eventually). At least I benefited as I completed my studies with that. A citizen from a poor country took benefit of the faulty system of this rich country. Its not just who are not paying the bank. There are a lot of foreclosures and shortclosures happening in this country because a lot of people cannot pay their debt.

Credit card company took a risk trusting us, they make money by making us pay the ridiculous finance charges, they aren't any saints either, but you agreed to pay them so its your ethics to pay them back.

By the way they don't look for your credit score while reentering the US. I don't think it shows in your criminal background check either, but yes, your credit score will be f**ed up.