All controllers are motion controllers. A gamepad just uses a different technique to record motion than a camera based system.
I want a motion controller that allows me to control a game like I would smoke a fine cigar or drink a strong coffee from a delicate porcelain cup or gently stroke the skin of a lover.
Exactly, humans primarily use their hands for physical interaction. Using locomotion makes more sense in a social / emotional setting ( although face + voice are more significant ).
If you've ever seen a novice gamer fumble around with a gamepad -or even a mouse for that matter- you'll know that this is extremely subjective. Gamepads are far from intuitive or comfortable to the unaccustomed player.
Touchscreen is probably the most intuitive ( mass-market ) interface there is at the moment.