The Wii U being less powerful is part of Nintendo's almost life long strategy.
That strategy is now no longer fit for a world where people buy cutting edge smartphones and tablets every year. When a 'home console' is not an object that inspires "wow, new tech thats better than the old tech by a fair margain!" responses, it meets the response the WiiU has.
Couple that with disastrous third party support, a price that has the non-started GamePad as an albatross round its neck, and a company that cant put out software to support two platforms well concurrently, and welcome to current loss-making Nintendo.
Next console has to be a hybrid, it has to be HD in both handheld and home (720p min for handheld), Nintendo has to dramatically beef up its 'games as a service' unit so Virtual Console and the like arent a joke, Tomadachi Life/Animal Crossing should transition to OS level, and from there you access old consoles and the added pomp and flair that adds to digital downloads, and software prices overall need to take a slight dip.
Ultimately, the aim should be to create 'Nintendo Life' so that when the seemingly inevitable hardware platform blur reaches terminal velocity, Nintendo have a platform to push onto other devices if/when they can no longer compete in any way with more aggressive hardware makers.
They have the next 5-6 years to do this, and hopefully they're instigating it essentially right now.