I think it's just a lack of leadership and Nintendo either being too greedy or indecisive.
They're straddling both a hardcore and casual audience. They're hoping that the tablet interface would appeal to non-hardcore gamers, and that they could still retain and possibly attract a hardcore audience with the more traditional thumbsticks and controller design.
So, in the end, they released a console that appeals to neither audience. It's too limited in terms of function that the casuals care about (portability and non-gaming use) and hardcore fans care about (power, third party support).
They reaped the benefits of their blue ocean strategy (looking to new customers and appealing to them rather than your old customers), and now that they lost both the new and old customers, they're trying to get them both with the WiiU.
