Nintendo stole it first!!!! lol
I think a lot of people get confused between invention and making something standard. Nintendo rarely invents but when it comes to making odd features standard equipment Nintendo are #1.
This is one of those damned if you do and damned if you don't situations that Sony seems to get into a lot these days.
Exactly. Think of it like the iPhone. It basically revolutionized phones and the use of the touchscreen. Everyone brands a motion controller like the Move "a complete rip off" but you don't call a thousand touchscreen phones "iPhone rip offs." Motion controls became standard and if they tried to be different, you'd get the Kinect. Which did well but has no appeal to a "hardcore" audience.