I'm not a Ninty fan, but I remember that at the apex of Wii's success my craziest prediction was: 140M with little effort, 160M with more efforts, 180M with total commitment and 200M with total commitment, no errors at all and incredible luck. Back then it looked like just production capacity could stop Wii from growing even more, and the fact that users didn't care for fancy graphics made it appear future-proof. But even then I never predicted PS3's demise, as it started doing better when Wii was growing at an incredible pace, and it grew also during periods of good sales for XB360, showing that each console managed to cater for little overlapping market segments (even now only a few great blockbusters show big overlapping between XB360 and PS3, obviously outside of them there's still a great degree of independence between their respective targets).
Ninty can only blame itself, not third parties, as since the beginning Wii's user base, unlike the DS one, showed it was perfectly fine with almost only first party games, not to mention that before Kinect, Wii + Balance Board owned almost exclusively the fitness and dance market.







