Is it necessarily a bad thing to be a net debtor? Generally when a business or country borrows money it's because they can put it to some productive use that generates a greater return than the cost of borrowing. If the US is borrowing money, it means that it's making productive use of other countries' assets and getting return from those assets that the other countries are not. This should be a good thing (for the US).

People tend to react to news about national debt like it's their credit card bill that they ran up on takeout food and flatscreen TVs. It's not really the same thing.