Given Move isn't setting the world alight (still below 10m Move controllers sold WW after a year, 4 months isn't it?, and that isn't even possible userbase as a portion will buy 2+ controllers) and Kinect wasn't as steller in the holiday season as people expected (probably only around 5m, 3m bundles, 2m standalone at a guess.) That's 3m/8.2m~ 360's that were Kinect bundles.
Wii just peaked like consoles of past always did after their 3rd year. It was a very consumer driven product and once they were off to the next thing (iPhones and iPads) it doesn't matter what 360 and PS3 offered, Wii was gonna drop hard. That's not to say Kinect hasn't had some impact, at least in the states.