In fairness, if credit card processors hadn't been permitted to require that and customers had had to pay the fee, credit cards would never have achieved liftoff.

Which is maybe as much of an argument as any, if it had put pressure on the processors to minimize or eliminate the fee and find alternative revenue streams to sustain themselves and build out the network. Instead we got a world where the fee has been static forever and the gains from automation have gone to cashback and rewards programs for customers, ultimately making it more expensive to pay with cash.