People must have hqd much higher expectations than I did for Smash U in Japan. Hardware sales are perhaps even lower than expected (though this happened everywhere) but Japan have been terrible for the Wii U and for home consoles in general for a while.
Also you could look at this and say "3DS version killed Wii U version in Japan", my interpretation is more along the lines that Nintendo knew that nothing is doing well on home consoles for the Japanese so the 3DS version was to make the Super Smash Bros successful there... Yes the Wii U version might have done better without the 3DS version, but not 2 million better. Seeing Smash 3DS doing pretty well in Japan you kind of realise it was probably a Japan-driven thing, and I expect that it will remain the primary version there while the Wii U version will be the better version comparitiverly in the West.












