Well first of all - it's the same problem as using a credit card to pay for anything you can't really afford! However it has a special "bad omen" significance

Well first of all - it's the same problem as using a credit card to pay for anything you can't really afford! However it has a special "bad omen" significance in regards to running your own business because sometimes you hear stories of someone whose business is not doing well, and they won't admit it and instead ruin themselves trying to bail out the business out of personal funds, such as running up a huge credit card debt. That's not to say that this guy is going to do that, but just that in general you cringe when you hear of someone using a credit card to fund a business.