Good point.
Though, not being a dev, i think at least that unbinding the unbindable keys does not require a lot of time of work. I mean, the key exists, they just have to unbind it. Again, i don't know how this is done, but it seems such a small task compared to the rest of their work on the game.
If someone could explain to me the benefits for them to bind the keys in the first place, i'd be happy, because i don't see why this happens. From my point of view, it's just laziness and seems a little thing, compared to configure the AI of the game for example.