It was doomed conceptually from the get go. There's no amount of Mario Kart or Mario or Smash games that would save it, those just bring in Nintendo fans.
There is no market for a "casual" system, Nintendo just hit the jackpot once in a limited window of oppurtunity, the bubble had already burst before 2012 as the Wii was falling off the face of the planet in terms of popularity. People were already losing interest in a console primarily driven by mini-game experiences
You either make a console that is basically a Playstation 4 or you can't have success with the way the industry is now.
Consoles are for big screen, big budget types of experiences. Smaller, quirkier, more accessible types of arcadey games are being overserved by the mobile market. Anyone in the middle is screwed. Unfortunately for Nintendo they're right smack in the middle. It's not just Nintendo either, Sony probably won't find a ton of success with LittleBigPlanet 3 either, just like Puppeteer and Tearaway flopped. People want things like Destiny if they're buying a console.