This biggest barricade to this would be people getting their bitcoins then charging back orders. Credit card companies/banks/gateways etc are very generous with customer charge backs, it can be challenging to beat fraudulent charge backs when you have a clear shipment and delivery of a product (not impossible). With something like a bitcoin (and other digital goods), there is nearly no chance you'd win and anyone who does a chargeback would get a refund. To a scammer, it could be a perfect way to get funds from stolen card numbers as well.
That said, I've considered accepting payments via Credit Card and physically shipping a wallet.dat on a CD file to a customer's billing address- that way I have proof of delivery and a signature, would help limit this type of fraud.
Of course.
I've long ago dismissed easily reversible methods as a viable business for any bitcoin seller, like VISA and Mastercard.
I can see anyone offering this payment option being hit with fraud.