I believe the userbase that have a Nintendo console tends to buy few games (child, adults, moms, whatever). Because of that, most of the games the userbase buys are mostly Nintendo offerings, so third parties have less room to succed than on other consoles.
Proud to be the first cool Nintendo fan ever
Number ONE Zelda fan in the Universe
Prediction: No Zelda HD for Wii U, quietly moved to the succesor
Predictions for Nintendo NX and Mobile