In some senses I'm quite proud that Walmart and BestBuy are making a stand. While I'm all for the ubiquity and convenience I'll receive with

PAY as an iOS citizen these upcoming security mandates were a real chance for transaction facilitators to come together and unify the crap out of this instead of giving poor old merchants yet another bloody rub.
Apple have strong market share but they aren't the only smart NFC device provider and with their locked in proprietary nature, not playing nice with the other guys (Android, for one) is going to lead to some stupid AT&T vs Verizon type split for coverage and support, all at the cost of precious resources.
Good on Walmart and BestBuy for choosing a solution that supports all customers, send a message to these overly rich executives that some things need not be a competition.
(Google Wallet + Apple Pay) Future Ca$h support POS for the win.