VGPolyglot on 14 December 2017
One thing that you didn't mention that I think is important is that the GameCube itself was originally supposed to have motion controls:
"Nintendo actually patented and developed a motion controller for the GameCube—Rogue Squadron series developer Factor 5 even experimented with implementing it in their games. Obviously, the controller was scrapped."
https://kotaku.com/the-gamecubes-secrets-revealed-1642812416
