I love motion controls in Metroid, I actually think that Metroid Trilogy is game for which Wii motion controls best suit.
So you basically saying that Metroid on Wii wasn't so popular because of Motion controls and that is not true, actually Metroid motion controls on Wii were more fun, easy to use and very practical.
Also you cant really compare Splatoon and Metroid in any case and Splatoon definatly isnt so popular becuse dont have controls like Metroid on Wii. Splatoon is basically Mario Kart of shooters, game with huge market appealing and can be played buy people from 5-99, Metroid was always hard core game with much smaller appealing for just specific group of players.
About you desire for new Metroid Prime game, I am sure we will have new Metroid Prime on NX.
