I don't have the sources handy but as I understand it he's given two reasons:
1) In an interview with Kotaku (via
Zelda Informer) he mentioned:
"But after developing the game and playing the game we realized that having a smaller version of the map on screen is actually better so you know where you are at all times. So we decided to take it that route. Obviously if we find that theres a great feature we could add to the GamePad, there is a possibility that we could do that.
2) In an
interview with WIRED he said:
"We realized that having something on the GamePad and looking back and forth between the TV screen and the GamePad actually disrupts the gameplay, and the concentration that the game player may be experiencing. You have your cars GPS system on your dash. If you had it down in your lap, youre going to get into an accident!"
Both essentially say the same thing: that a detailed, more intimate GamePad map that you might want to stop and look at every now and then isn't as good as an on-screen minimap in real-time gameplay. So you'll probably only be able to bring up a bigger map and have it obscure the screen.
That's fair enough, to be honest, but I wish the mini-map wasn't so detailed in the first place, or can be hidden. Zelda's always been great at offering minimaps which don't give away too much information to the extent that you play the game on autopilot, instead asking you to really observe and explore your surroundings.
Metal Gear Solid V showed that it's possible to make an open world game that doesn't give the player a dependence on the minimap, so it can be done.
Compare and contrast the above statements with what Aonuma said after The Game Awards in late 2014:
"Recently, I've taken to relying on the map on my smart phone when I'm out walking in a place I'm not familiar with. A map isn't something you keep tucked away in your bag, it's by holding it in your hand and being able to constantly check it as you move forward step by step that gives you that sense of adventure."
That's the kind of map I'd like, really. It's more immersive to check it momentarily (much like how you'd pause a game to do so) and then explore, than rely on a minimap like a GPS.