Nintendo isn't ready for next gen.

[PAOerfulone]

I don't think he meant, a 3rd party game selling systems directly. Just having a good quantity of strong 3rd party games to back up the 1st party games to finally draw in the people who have been on the fence about it because, despite the Nintendo console having all the high quality 1st party games, that's ALL they have.
The people who already have a Wii U are people who were going to buy it regardless of whether or not it had 3rd party support, but if it DID, sales would be considerably higher. The Wii U would be on track to outselling the GameCube and potentially the Nintendo 64 if that were case

Think of it like this:
SNES sold 49 million, with a strong lineup of quality 1st party Nintendo games, backed up by healthy 3rd party games, despite SEGA breathing down their necks.
N64 sold 33 million, with AGAIN a strong lineup of quality 1st party games, BUT  weaker supply of 3rd party games, because most of the big ones (Final Fantasy, Street Fighter, Mega Man) went to the PS1.
NGC sold 21 million, with another strong lineup of 1st parties, and slightly more 3rd party support, but still weak compared to the Xbox, and especially the PS2, which got Grand Theft Auto, Final Fantasy, and Kingdom Hearts.

And now the Wii U, currently at 10 million, is on track to being the worst selling Nintendo console ever due to the weakest 3rd party support they have ever received despite another strong output of quality 1st party titles.
3rd parties games may not be an immediate system seller like say, a Batman Arkham Knight bundle, or a Kingdom Hearts 3 bundle (I'd buy a PS4 or Xbox One in a heartbeat if that happened), but they're definitely a lurking variable.