The real issue for retailers is not Apple Pay, it's credit card companies.
Apple Pay got all major banks on board because it uses the existing credit card system, thereby making it even more indispensable than it already is.
MCX CurrentC is an attempt to bypass the up to 10% cut (or fixed amount + %) that banks together with credit card companies charge merchants on every transaction.
So while I am thrilled about Apple Pay and have been avidly using it since day 1, I am not a fan of credit card companies. They have too little competition and merchants are too much in a position of weakness to negotiate anything better.
It might not be a problem for Walmart, but I was talking to my watch repairer the other day, a 50-year old 1 man business, the guy is genius with watches, but he's no lawyer or accountant. And I felt bad for him as he was reading through Visa's contract and had no choice but to sign it no matter how outrageous its terms were.
I'm not saying MCX would help him directly, but if there's any chance it creates competition against credit card companies which indirectly forces Visa/MC/Amex to lower their rates, the real economy, small entrepreneurs, will win.
And in parallel to that, we the customers are constantly on the hunt for credit cards with even higher benefits, like 5% cash back, and who ultimately bears the cost of that? Retailers, because credit cards are still getting their usual cut no matter, on top of whatever cash back they give us.