Shigeru Miyamoto is known for creating some of the best games ever made, some of which necessitated a few revolutionary hardware designs to even be able to play them properly.
While his game-making style hasn't changed too much over the years (still mining those hobbies), Miyamoto explained to Edge that over the years his role on the hardware side of things has increased.
A long time ago, my role in designing the actual hardware was really limited – mostly it was down to designing the controller, or the controlling interface, or some of those special features that you want the hardware to include on the software side, to make design and development more efficient. It was all about simply making better software. But I think, probably from around the time of the DS, my involvement with hardware has significantly changed. With that project and onwards, I’ve been able to significantly oversee the overall development of the hardware as well as keeping an eye on the software side of things.
As long as he keeps producing insanely fun games, we don't care what department Nintendo puts him to work in.