Honestly, Nintendo just needs to keep failing and go away. There has generally never been room for three major consoles in the core gaming market. There's usually been two main consoles, and then one or two other irrelevant machines in distant third or worse. I guess one exception would be the PS2 generation since the GC and Xbox were close for second, but both way behind the PS2. Last gen bucked the trend too, but just becaue the Wii found a market outside the gaming core.
We can talk our heads off about what they should do, but the fact is there just isn't room for a Nintendo console. Most prefer Sony and/or MS now and there not much they can do to change that now. They've messed up with fore gamers for too long. They're viewed as antiquated and for kids, and not providing the online experience, "mature" games etc. that today's core gamers expect and want.
Portables are a different story, but that's a shrinking market as more people and kids move to phones and tablets for portable gaming.
In any case I don't regret my Wii U or 3DS purchases by any means. But I'm pretty set on never buying another piece of Nintendo hardware. It's just not worth it for the ten or so first party games a generation that interest me. If they ever go third party or merge with Sony or something i'd gladly buy their games after this gen. But otherwise I'll get my fix now and go without going forward.