Hmmm, well I can't say it surprises me. A lot of people predicted a Nintendo crash, and here we are. It doesn't surprise me that interest in the whole motion gimmick wasn't enough to sustain a second generation of the same thing.
I'll also say that while I like some of their stuff, I don't have the investment in the usual stable of Nintendo IPs that a lot of other people do, and truthfully it doesn't surprise me that this core audience is slowly fading with time as well, and/or aren't excited to leap at new hardware upgrades.
The thing is that the Wii systems have very few games that really excite me and saying "wow, I've got to play that" and a few like "Fatal Frame Zero" never make it to the US. Just to get some of the more successful RPG franchises into the US basically involved a massive campaign and forcing Nintendo and the publishers to localize them, kicking and screaming all the way. Needless to say the energy to keep doing that with decent games doesn't hold up.
See with the 3DS there is a decent stable of games I actually like and want to play, with a pretty robust release schedule. With the PS4 there might be crap for games out there, but I know from experience they are coming and trust that compared to Nintendo where a comparative drought is the norm, and it seems like all the games I'd want to play aren't available in the US, and by the time they make it here I've become invested in other things.
Truthfully, I think a management shake up is just what Nintendo needs. That, or someone in charge should seriously considering selling Nintendo before the brand is totally worthless, perhaps to either Sony or Microsoft.