I don't know if they got the idea from Google Cardboard or not, though certainly there are similarities. But the idea of producing shells to strap to phones and such came around before Google Cardboard, I think. I have a Viewmaster from a few years back, for instance. Nintendo has just been reluctant to move into VR, I think, because the cost to consumers kind of goes against what they have found works best. But this approach... could be okay. As so many people have a Switch in their homes or will soon, you're down to a cost of only another $40 to add probably a very consumer-friendly approach to VR. So I think it could do very well. I know I would like to try it!
"Too often we enjoy the comfort of opinion without the discomfort of thought." - John F. Kennedy on reality
"What if everything you see is more than what you see--the person next to you is a warrior and the space that appears empty is a secret door to another world? What if something appears that shouldn't? You either dismiss it, or you accept that there is much more to the world than you think. Perhaps it really is a doorway, and if you choose to go inside, you'll find many unexpected things." - Shigeru Miyamoto on secret doors to another world