Here we have a classic problem. There's not much use of NFC in the United States (at least, not as extensive as in other certain countries), which means that Apple isn't compelled to include it in the iPhone. However, the adoption level is lower than it should be right now
because Apple hasn't adopted it. At the same time, if Apple did include it, we would see NFC adoption rates go up. Yea, Apple has this much influence.
Anyways, if the iPhone got NFC just now, how would they explain it at the unveiling? It may be a bit difficult to explain at this point in time. "We noticed that many of our competitors have NFC, so in order to compete we have included NFC in our phone."