I understand Miyamoto's view in seeing the competition as creating Kinect and Move just to inch in on Nintendo's turf with similar games to Wii Play and whatnot. He is absolutely right in this regard.
However, I disagree with the premise of "The Wii was out first, Wii created motion controls, our competitors doing motion controls = blatant copying, and therefore they need to find something new." What this view fails to take into account is that both Move and Kinect have different titles coming out for them and compared to the Wii. Sony with the Move lineup seems to be trying to incorporate their core games with the Move. Microsoft with Kinect appears to be more or less whom Miyamoto is referring to in the OP.
My view is this, Nintendo with the Wii gained a lot of traction because the motion controls were and still are viewed as a unique novelty from Nintendo. Combined with a software library that looks more early Super Nintendo years with the motion controls, while your competitors are in a Red Ocean over the "core," then you win from the get go.
However, motion controls are just a platform. Once all your competitors have motion controls via Move and Kinect, then the dynamic changes from a Blue Ocean owned and operated by Nintendo to a Purple Ocean, which can stay Blue or devolve into a Red Ocean if your competitors start emulating your software library and putting out a library similar to Sega during the Genesis vs. Super Nintendo console wars of 1990s.
Nintendo saw this coming and this is why the 3DS compared to any platform since the SNES has the most 3rd party support. Nintendo foresees increased competition in the 8th generation and they want to alleviate any losses in the Blue Ocean by catering to the "core."
This being said, the wildcard here is smartphone gaming. In 2004 and 2005 when the DS and PSP were released, gaming on cell phones was in it's infancy. Nowadays with smartphones able to put out PC gaming graphics, Nintendo needs the 3DS more than ever and 3rd parties to counter both losses in the Blue Ocean to Move and Kinect and losses on the handheld side to smartphone gaming.
This is my view, it differs from yours, I could be wrong, and please correct if I am.
