Because I've had an XBox One and I'm no longer going to play this game. Holiday season is fast approaching so maybe someone can get or give a nice gift.
Actually, there are a lot of us that have an Xbox one. I auction off and bid on games here very often as well as several people. Anyhow, Nice auction. Fanned, watching and definitely bidding. :-)
It's not mandatory. The game can be played with or without a Kinect sensor. There is a button command to initiate voice commands issued through the Kinect.