There's nothing intrinsically wrong with being in debt. Companies will borrow if they think their return on capital will be higher than the interest rate they pay to borrow the money.
E.g. if a company like Wal-Mart has to pay 0.5% interest to borrow money, that's fine if they think they can take that money and invest it in a project that returns 2% over the same span of time. Then that's a good use of someone else's money.
Or if you take out a mortgage and buy a house and the interest rate on the mortgage is 5%. That might sound like a lot, but if the value of the home appreciates more than that amount per year, then you've got a good deal and you'll make more money in the end (and plus have a home to live in).