This is from a recent interview with Edge Magazine. Basically, Miyamoto isn't a fan of the Casual Gaming Market and would much rather stick to Core Gamers in where he can make less games that are the equivalent of a lousy smartphone game.
Source: http://www.gamnesia.com/news/miyamoto-nintendo-is-focused-on-core-gamers-not-passive-ones#.U_4Ya8EpDQ8