The only Wii game that Nintendo's put out that's genuinely lacking in quality or could be considered "bad", (besides Other M, but at least Team Ninja TRIED, it wasn't like they just didn't care) was Wii Music.
All the shovelware on the Wii pretty much amounts to third parties looking at Wii Sports and Wii Fit, assuming that Nintendo put minimal effort into it just because its not a graphically intense, in depth adventure, and then assign their third string teams to cobble together a "Wii (noun/verb)" series wannabe. Then they start complaining when their game sells poorly and blame Nintendo for "dominating the market" with their own games.
I think Miyamoto actually said something to the effect of "Don't assume our Mii based games are just rubbish we slapped together. We put our top teams into those games, third parties have to do the same if you want to sell well.".
That aside, "Nintendo is doomed" is pretty much par for the course whenever Nintendo's on the verge of their greatest success yet.