Nintendo consoles are like handhelds in the eyes of big Western developers,barely anyone takes them seriously.
Ninthings always argue that Nintendo games are soo good that third party cannot compete even in wildest dreams,but reality is a bit more complicated.
Nintendo has some kiddy stigma attached to them,maybe unfair maybe not but Nintendo is fully embracing that(kids friendly machine,approving anything that has potential to bring $$$).Big Western devs treat it like that,target audience=5 year old kids(or people that have no clue about gaming).As said above even developers facing bankruptcy would rather go insolvent than work on the Wii...that tells a lot
But even more importantly audience is treating it like that,want to play GTA,Halo,MW,RDR,Bioshock,Mass Effect,Assassins Creed,Bayonetta,Crysis 2,etc like games buy anything except Nintendo...even dirt on the road is more useful for that purpose than Nintendo console
What kind of lunatic would buy next-gen Nintendo console in hope to play those games?
Two things that are biggest stumbling blocs for Nintendo
-archaic online system
-reptilian age hardware
They can fix those things with money,but do they really want to?
Imagine a world were Nintendo console fills the headlines as "shooter box,mass murder simulator,violence inducing console,sex sex sex"