Nintendo details why some of their games get voice chat while others don't

Coming from a NintendoEnthusiast interview with Nintendo representative Julie Gagnon...

“The thing with Splatoon is that the game is so visual and we really feel that the people in the game do not need voice chat in order to communicate with each other because we have ‘oh, stay here’ or ‘come here’ icons. We have many ways to communicate in the game. Plus, with the gamepad and the view, you can easily see if one of the members of your team is in trouble, or if there is a part of the map that you need to cover. So, this is something that we made a decision on so that the game can appeal to the maximum number of players. So, ultimately, the developers need to decide, depending on the features and the game itself, whether voice chat is included.”