It had an impact, that's undoubted. But the loss of the casual marketshare is in majority due to Nintendo letting it go. And like I said, if it was not motion controls, it was another knock-off hit, that Nintendo has proven time and time again capable of creating out of thin air.
Like many say, only Nintendo can kill Nintendo.
Because good motion control is the logic evolving around some arcade games. Nintendo is the last major arcade producer in the console market. Sega gone, Atari gone. The arcade type game is the Nintendo mastercraft. And aways explode in sales when evolved the arcade type of game. Nintendo master racing arcade (mk) game, fighting arcade games(smash), open-world arcade games (botw), etc. Wii sports and wii fit is arcade games applied with motion control. The motion control response, with Microsoft and sony, is more computer games like visualized motion control and fewer arcade games, that is one the major drawback around Microsoft and sony initiative: their origins is around computer games and not arcade games. Nintendo stop producer big arcade games in 2011, Zelda is the worst Zelda ever and less arcade game ever. Metroid Other M is a cinematograph computer game in a console arcade type. The last medium-big game is Donkey Kong Returns and the last to sells more than 5 million. The switch has better motions controls and betters motion feedback.