Given that Move and Kinect are both peripheral devices, the fact that Move outsells Kinect 2:1 isn't useful without information on what the sales ratio of the PS3 is to the Xbox 360.
If the PS3 outsells the 360 in Japan by more than 2:1, then technically the Move is failing there, as well.
I'm pretty sure the PS3 does outsell the 360 by more than 2:1 in Japan. It's probably closer to 10:1 than it is to 2:1. That makes the difference even more substantial. If one assumes that motion peripherals are equally popular with PS3 and Xbox 360 owners, then the attach rate should be the same. Even assuming that one considers that many PS3 owners don't need the Move if they already have a SixAxis, that still indicates there should be a much bigger gap between Move and Kinect than 2:1.
That will, of course, tail off. Kinect sales will slow when every Xbox 360 owner in Japan who wants one has one, and Sony will still have a large addressable audience for the Move if they can create compelling games that use it.