Phil Stortzum of SuperPhillip Central writes, "The Wii U's November numbers according to the NPD were around 250,000. That is with a new 3D Mario game that just released, Super Mario 3D World. Now, one could argue that this was because the game wasn't a "true" 3D Mario like 64, Sunshine, or Galaxy. However, Super Mario 3D Land is the best selling 3D Mario anyway, so that argument falls short, as it does going off of the quality of World and it being a phenomenal game.
However, what Nintendo faces now is a system that is selling historically low, performing worse than SEGA's Dreamcast and much worse than the "failure" that was Nintendo's own GameCube (which at least the company turned a profit on, unlike the Wii U currently, which Nintendo takes a loss on with each system sold). While I've gone into the abundance of reasons why the Wii U was disastrously mismanaged, we can add another reason to the list-- there's just way too much Mario. He's not the system seller that Nintendo thought he was for the Wii U."