Actually it is part of the problem: During the lifespan of the Wii, consumers were attacked with lots of "Wii Something" stuff, like Wii Fit, Wii Music, Wii Sports, Wii Motion Plus, Wii Play, Wii Party, some of them with their mandatory accessory... then you release "Wii U", that looks like a standard Wii with a new controller. The consumer wonders why they don't sell the controller standalone (I've seen some actual cases of people thinking this), and, therefore, think the controller is stupidly expensive considering how cheap the Wii is right now.
The Wii U lacks its own identity as a product, despite being a great product. Then you add the fact that there are not many games for it right now, and the fact that Nintendo is failing at marketing it right now, and at the same time failing to promote the fact the console can do so many things the first Wii can't... It's the perfect formula for bad sales.
But luckily, this can be fixed, and I'm sure Nintendo is already working on all of this.







