LeaseRig can shield providers from this risk and there are ways to deal with it if not completely avoid it, i.e. use the full scope of security measures provided by the card issuers, verify buyer's identity, limit amounts etc. If Coinbase can sell BTC that way I'm sure it is possible to work this out. It would be costly though and would probably have to involve an extra fee, so the question is whether there would be enough demand for that.