I'm only surprised it has taken as long as it has for Nintendo to fall so hard. What a shame that such a once-great company has become so irrelevant to core gaming.
If you go back to the Revolution discussions I kind of defended them tooth and nail.
Then the Wii was announced and I was cautious at best. Then it was released and yeah. I still don't own one. For four generations the Nintendo dominated my console gaming, now I'll almost definitely get a PS3 but not a Wii (well, I never owned an N64, either, but played it nonstop from roommates. I had roommates with the Wii, too, but it didn't get used much., and the PS3 is mostly for bluray at this point.)
I always claimed that the GC and the N64 were great systems due to Nintendo's games (and this is why I felt those rumors of Microsoft acquiring Nintendo back when Nintendo was on the ropes made perfect sense.) With the Wii that proved to finally strain. Third parties went from weakly supporting to mostly abandoning, and Nintendo's games went from fun and innovative to pretty much derivative.