The Bitcoin ledger doesn't provide credit. There's nothing stoping someone from offering a credit account (e.g. a consumer credit card) denominated in Bitcoin.
It's definitely possible to offer a credit card transacting in bitcoin though it would have a number of technical differences. One big one is that the settlement process would need to be immediate, otherwise the transaction would be rejected. With a normal credit card transaction the funds don't actually transfer till the end of the day (if you're lucky) or the next business day (most of the time). With a bitcoin backed card it'd need to be immediate and the credit card company would need to have the bitcoin "at hand" at the time of the transaction.
A better, tough far from perfect, comparison would be to sending money through mail to later receive the goods, or a debit card sans the paper trail.
The article starts from a fallacy, but that doesn't mean it's point is null.