Admit it, how many people do you know bought a Wii and only played Wii Fit or Wii Resort?
*Puts hand up*
To be honest, I always figured it was because the software houses couldn't really think outside the box.
For years we've had just about the same way to play everything. Minor cosmetic differences from one gamepad to the next would pretty much be the only difference. Whether or not it made them lazy or complacent, who can say, but now, all companies like Activision, EA and Ubisoft know how to do is make the one title and just port it across.
That's why the only titles worth buying on the Wii are Nintendo ones, because they were tailoring games to get the most out of the unique hardware. Companies like Activision don't give a shit about not being taken seriously, they only give a shit about making money. End of story.
As per the usual, Nintendo will do cool things with the Wii-U, but only Nintendo. That said, I don't see them making nearly as much money this time around because they're obviously not catering to the simple casual market. At its core, it's a 1080p Wii with an extra portable screen, and that's not going to be nearly enough for most.