Going on two years after unleashing the Wii U unto the world, Nintendo is still searching for compelling reasons for its tablet-style controller to exist. Sure, off-screen play is neat and a handful of games make novel use of the second screen; but it's just not enough.
Nintendo seems keenly aware of these shortcomings, and plans to come out guns blazing at E3 this year. During the Q&A portion of the company's recent financial results briefing, Nintendo president Satoru Iwata revealed plans to demonstrate the value of the GamePad by introducing multiple games only made possible by the controller.
I suppose we'll just have to wait and see. And speculate wildly in the meantime.