I agree. But long term, people will start taking the Kinect down and packing it away in the drawer full of gaming stuff they have if there's no reason to keep it connected. It's not an inconspicuous device and if it's not contributing to the experience, I for one would rather not have it up. I'm seeing something like PSEye. I bought it, played a couple of Sony's weak PSEye titles, and then it had no purpose and I put it away. Obviously the voice input is key to Kinect 2 and that'll be enough for a proportion of users, but there'll be others who want more to justify its presence under/over their TV.
MS need to show not only Kinect 2 titles that are worth playing at launch, but an upcoming library that proves it'll be a consistent boon to games, that devs are using it, and devs can continue to use it because it won't be packed away one day as everyone values the contribution Kinect has with XB1.
I suspect though that many will probably leave it up just for the automatic logging in bit based on face recognition and controllerless input from the couch.