Not even close.
Wii era brought in tons of casuals who bought the system for Wii Sports/Fit, and the NSMB + Mario Kart franchises cashed in on that big time. It was a perfect cross section.
Mario Kart 8 will sell about 1/3 of the Wii version IMO, but that's still a huge success and will be around 8-10 million copies life time.