The article makes some decent points. And if your looking for exclusive games with quality, Nintendo is a great choice.
But for many its nowhere near as simple as that. Its not that Nintendo doesn't "need" third party, they have no chance of having third party, and have no choice but to live off of their own output. If your not a person who liks Nintendo games as objectively high quality as they are, then obviously that being the whole appeal of the console falls apart.
And if that falls apart, everything else like it being cheaper, more power efficient and "portable' all fall apart as well.
The Wii U lives and dies by its software library implicitly of which there are only one kind of game. So, if you don't care about Nintendo games, the Wii U irrelevant to your choice of console.
Of course, the other two 8th gen consoles have their own issues as well, an anemic exclusive and third party library in 2014 with little to differentiate between the two makes them also irrelevant if you have a PC.
But i would say the Wii U's issues are much more concerning for its long time prospects. Sony and MS(especially Sony) have a great year ahead of them with a decent number of platform exclusives as well as a large stepple of third party games as well.
Nintendo, as usual, can only count on themselves, and YMMV on that.