That's what was always fascinating about the previous DRM debates. Under the previous plans, that Dead Rising 3 for $50 at Amazon would've been a "digital" game, and would play a part in adding the "digital game pricing competition from multiple retailers on a closed platform" that everyone supposedly wants.
Obviously, there are other restrictions that come along with that that were worth debating (so I'm not saying everything was 100% cool), but it was always weird when people were like "Microsoft will make every game $100! No competition!", as if Amazon would be completely incapable of having their own sales all of a sudden.
That said, let's hope Amazon and other retailers get into the process of selling download codes/keys for Xbox One games, like what seems to be happening for PS4 games.