I think that should have been their strategy for the Wii. By keeping their investment cost low on that console, they could have positioned themselves strong to release a console this gen that was at least on par with the competition. As I see it, that is the biggest hurdle to attracting devs to their system.
I think Nintendo still do not see themselves as being in the same market as Sony and MS, and as such, feel as though they need to differentiate themselves through their hardware. The Wii U, at $350 could be a significantly more powerful device if the gamepad didn't exist. The gamble there is, if the Wii U is equal to MS and Sony's consoles, does that mean people will buy it? Does that mean devs will develop for it? GameCube says no. 3DS kind of says no, but for the opposite reason(weaker hardware, better support than Vita). MS said they are pouring one billion dollars into game development for the Xbone, I don't know if/how Nintendo can compete with that.
I think the Wii U's lack of support from Nintendo stems from the weak 3DS launch which forced Nintendo to pour resources into 3DS development. Now, they are left scrambling to support a second platform, almost entirely on their own. There's a bit of the whole "chicken or the egg" debate when it comes to Nintendo's troubles. Ultimately, I think they need to lower the price of the console before Christmas significantly($50+), as the perceived value just isn't there right now. Things will get better for Nintendo if they can get their install numbers up, because they know there is a market for their games(again, gamepad cost is probably killing them right now, since they still claim to be taking a loss on each unit).
It's a difficult situation to be in. I think weathering this gen will be vital for Nintendo to be able to rebound in the next 4-5 years(they might think so too, considering their reluctance to drop the price), but this time, they will have to actually learn something from their past failures, not just say they did.