NFC is nearly useless at this point and there is a possibility it will never become ubiquitous. I don't see NFC being a huge selling point outside of the techies fpr quite some time.
I'm not saying that's the reason why Apple ditched NFC, but maybe we would need an independent study on actual stores which support NFC and consider if whether it's a useless standard. You're gonna carry your wallet anyway to pay in cash, why not put the NFC in the credit card?
Samsung and Nokia are popular enough and have the resources to back NFC but as of now they haven't done anything besides launching phones with the technology.
NFC today is just a dummy selling point and they know it, because they haven't done anything to make it popular.