I don't disagree with you but I also feel like that might be a "solvable" problem. I'm somewhat familiar with what AA attempted on the business side but that also had a lot to do with trying to force NDC faring, etc. It wasn't just related to using the credit card.

Not saying it will happen, but given the revenue to be shared via swipe fees, I'd say UA (and the other carriers) has a powerful motivation to figure out a solution to that problem, particularly for businesses where corporate airfare is direct billed (i.e. create some sort of "waiver" for those travelers, but require using the card for leisure travelers, etc.). To be clear, I'm not at all predicting this will happen, but I believe it would be naive to think it's not a problem they aren't interested in finding a solution to.

Clearly, the credit card piece of the airline business' are becoming increasingly important so I think its at least plausible to believe they will find "solutions" to impediments for growing that business...

Regards