Apple Pay requires you to put your card details into the phone, an insecure environment which leaked NSA slides claim to have full access to. With the recent celebrity hacking and the absolute facepalm of allowing remote dictionary attacks against iCloud they need to earn trust, not simply claim they are secure.
I prefer stored value cards and eWallet systems. In the former case you buy the card with cash and it's basically anonymous, beyond the fact that purchases can be linked. Simply return the card and get a new one periodically to limit that. The eWallet systems make the charges appear on your phone bill, so they don't store and credit card details on the phone itself and the per transaction limit is low.