Oh come on lol. The Wii U is old hardware. It's VERY dated and if you think that that hasn't had an influence in poor sales then you have to be mad. And let's be honest, poor sales have driven this to happen with Rayman. And I'd wager money that this wont be the only title to be affected this way over the coming 6 months I'm sure.
It's crap, dated hardware and it hasn't sold because people look at it and wonder, bar a touch screen control, what it does that a current gen system cant at half the price, with a back catalogue of near what, a 1000 games?
Granted, this didn't happen with the Wii, but the Wii was a one off, an innovation if you like which bought new people to the table who had never had an interest in consoles before. The Wii U doesn't have anything new that people are interested in.