“There should have been a Wii Sports-type game that let everybody get it. Those huge franchises would have gotten the loyal Nintendo person, but it was Wii Sports that got all the people outside the Nintendo world to look and say, ‘This is a really, really neat, fun thing to do.’
“I think there was something really special about the Wii and the way that whole thing happened that they didn’t even know was going to happen. I don’t think there was the possibility that the Wii U was ever going to repeat that. I’m not sure they expected that [either].”
– IHS Electronics & Media’s Senior Games Analyst Christine Arrington
Arrington does not give any details on her research, and the only concrete evidence she brings to the table is anecdotal. This appears to be purely speculative.