It seems as though motion controls are the preferred control scheme of choice for the majority of Splatoon players. The news comes from Splatoon co-director Tsubasa Sakaguchi who has stated in an interview that roughly 70-80% of players use the gyro controls for better precision when taking out other players.
“About 70-80 per cent of players are using the gyro controls. That’s not to say we’re forcing it on to them. From our point of view, we think that the gyro controls are the best way to play Splatoon, the reason being there are two main movements you need for a shooter. One is moving the body, the other is aiming where you’re shooting. In that sense, we think for Splatoon the gyro gives that subtle movement and more precise actions to be able to really experience the game in a much better way.”