Link please? I was watching the video on IGN and they don't say what you are saying.
For one, they were just commenting on Wii U having only 6% of BF sales, and saying "Does that mean SSB didn't sell Wii U's? People bought it but only people that were already on the Wii U?". Where are you getting that "they thought Smash will save the Wii U singlehandedly"? Lovely strawman sir.
Also why do you say it's from vgchartz? Aren't they quoting InfoScout data?
Yeah the inaccurate and flawed research of infoscout!:P