He and Nintendo were probably unsure if Zelda: Majora's Mask could spark the same interest as Ocarina of Time 3D. MM has always been the black sheep hanging out with the red-headed stepchild known as Zelda II. I would not be surprised if Nintendo used A Link Between Worlds to tease/market MM 3D in a similar way to how the Marvel superhero movies teased The Avengers.
The Zelda series is Aonuma's baby...out of all the games he's done, Majora's Mask is really the only Zelda game that's still graphically dated.
Old NES Zelda games have a retro flare, the SNES-era + GB-era Zelda games are timeless, Wind Waker and Ocarina of Time have both been remade, and the DS games don't look that bad when played on such a small screen.
But Majora's Mask is a game that Aonuma not only directed, it's the only one that needs some kind of graphical refresh.
Sometimes developers don't just do things for monetary reasons...sometimes they are allowed to go where their passions lie as long as it has a possibility of being profitable. Even if Majora's Mask 3D won't make a ton of money, Aonuma would very much do it for his own sake to keep the Zelda series up-to-date.
. The past two games have been a rerelease of a Gamecube game and a sequel/update to the SNES games. Don't get me wrong, both games look great, but give me a genuinely new Zelda!
