NFC payment devices actually use the same technology inside the US, too. I'm not sure where the people who are whining about fragmentation are coming from.
Whether you're using a card or your phone, you have to get something out of your pocket either way (which only takes two seconds anyway, unless you keep your phone on a belt clip). Typically all you have to do is unlock your phone and touch it to the device, no need to open an app (although depending on your security you may be asked for a PIN).
And if unlocking your phone really bothers you that much, it's possible to modify an Android phone so that the NFC transmitter is on even when it's locked, but that's kind of insecure since somebody could just brush a reader up against your pocket when you're not looking.
The attractiveness of using your phone is that it works just as well as a card (if not better, since nobody can access it unless your phone is unlocked) but you don't have to carry around an extra card.