Xbox 360's were The Original Netflix Machine of that 2008-2012 range. Sure maybe Wii's sold more but they only effectively played Wii Sports and didn't support Full HD. Sure PS3's had blu-ray drives in them but people were beginning to stop caring about physical media. The most popular "game" in terms of hours played on the 360 was the Netflix App.

So because of that, I'm not surprised that casual audience also got a Kinect at some point too. Because of the Netflix app, you always had your 360 plugged into your TV.