My main gripe about this is that I honestly don't think MS really want to spy on me when I play games.
People crying big brother etc. is silly, because it's just when I'm playing games, the one time when my people watching my activities matters the least. If I'm worried about anything it's those Google glasses, people walking around constantly filming more than they already do now with phones etc.
But yeah, that QR code sensor idea is good, just saves time.