Apple hasn't always implemented things that work perfectly the first time (hello MobileMe), but I would rather a company wait and be all-in when implementing something than push a nascent technology out to customers and set it up for failure. Apple knows that the competition has already adopted NFC and yet decided not to include it in iphone 5. That doesn't mean Apple will not implement NFC in the future when it makes sense from a business perspective.
Will Apple fanboys do a 180 it if the 5S comes with NFC? Sure. Will it be justified? Probably, given Apple's history of making products that 'just work' predictably and practically for the end user, and across its huge global user base
Here's an article that IMO is fairly balanced:
http://www.computerworld.com/s/article/9231257/iPhone_5_Why_no_NFC_
*I'm an android user, never owned an iphone FWIW*