I think it is party due to marketing, but I don't think that's the only issue with the Wii U. Other issues include the fact that there's no killer game that explains why the new controller is really needed (most games just mirror the TV to the controller, or show inventory or a map on the controller), the fact that there's only one controller with a screen, so most games that use it have asymmetric offline multiplayer gameplay (which can be difficult to explain to people), and the fact that playing the Wii U doesn't look as much fun as playing bowling or tennis on the Wii did.

Don't get me wrong, I think the Wii U is a console worth owning, and right now, it probably has the best games library of all current-gen TV consoles. I also think that poor marketing and misguiding naming play a role in its poor performance — why not call it the Wii 2, to clearly show that it is different and new?

But I don't think that its failure can be attributed solely to marketing.