Buying time to prove security?
I expect that Apple will need time to prove their security model, and that the structures in place will work. With a bunch of credit cards loaded and a mere fingerprint for authentication, isn't that an attractive target for hackers? Should Apple one day open the API to developers, the API itself and the approval process must ensure that apps aren't leaking information, maliciously or accidentally, similar to discoveries about apps that can access your location or contacts without really needing either. The benefits of the iPhone outweigh the risks or shortcomings. By extension, Apple Pay will probably be good. But they need to make sure this is done right. The barrier they must overcome is high - make it easier to pay using my phone than taking a card out of my wallet without exposing me to more risk. Hopefully Apple has a good team of people that can think like bad guys.