The Wii was overhyped though. Most players never bought any other game than Wii sports. I had an unlocked Wii and played all the good titles, and there are not more than ~10 of them. Most Wii games (looking at you, NFS) felt like half-baked mobile ports.
And the Wii U sales showed that. Yeah, the Wii sold to tons of casuals, but hardly any of them upgraded, even though the Wii U was a much more capable system.
The most frequent question I hear to this day when talking with former Wii owners is "What's the benefit of the Wii U and why would I need to upgrade?" That's a question I have never heard in relation to any other game console. Or have you ever heard the sentence "What's so special about a PS3 if I already have a PS2? Why would I need to upgrade?"
And this setup the Wii U to be such a huge commercial flop that Nintendo effectively cancelled their stationary game console line.
I would say it was seriously overhyped, similarly to the Netbooks. It was a fad, it was cool, boatloads of non-techy-people bought them, and none of them bought the successor so it all died quickly.