No one would be complaining about late 2008 if Nintendo had released a bunch of exciting games in early 2009. Very few will be complaining in two months if they announce a bunch of awesome games at E3. No one will be complaining once those games actually come out.
People always complain when there's something to complain about, even if it's a little thing, and the longer the problem persists, the more people join in on the complaining.
It's interesting to think that Nintendo's increasingly negative reception from gamers could be more a problem with their release strategy than with their actual production focus. But the main reason people are complaining now is that for going on 12 months, at least in the non-sales related and hard to measure category of how excited gamers are for the new games on a console, the Wii has been getting trounced by the competition.
I'm sure it will change as well, but you might as well let the competition have the scraps they actually deserve while it lasts...











