In the end I think Nintendo is really to blame here. For so long they saw that third parties had refused (this is what happen and they admit as much from the very start) to release traditional games on the Wii. I don't mean casual vs hardcore I mean simple traditional games in traditional genres. Fighters, RPGs, third person shooters, etc. Instead of a fighting game Nacmo gives Soul Caliber Legends. Instead of a proper Resident Evil after releasing RE4 Capcom gives the Wii rail shooters. Etc. Only Nintendo addressed things and even then it wasn't in full force until last year. As a result I think people just tuned out non-Nintendo games and the Wii as a source of traditional games. There are good ones now but they certainly don't get the attention they deserve. I can't think of any other reason why they aren't getting bought other then that. People just don't care anymore because that there was nothing to care about before. Third parties refused and Nintendo wait to long to do anything to fill the void. Voids they knew that had to be filled after what happen with the GameCube when companies refused to release games on it.
I actually fear for the next Nintendo console if Nintendo doesn't come up with a solid release offering. The Nintendo 3DS has that now with Super Street Fighter 4, Ridge Racer, Madden (ugh), Splinter Cell, etc. Traditional games not off the wall "3DS games" the developers tried to make games that fit the "Wii experience". No weird spin offs no one was asking for. Do that and people walk and I think that's what happen with the Wii and why The Last Story's sales (same for Xenoblade's) are the way they are in Japan. The same will happen in the US I'm afraid. The damage is done and it can't be undone.
The conspiracy nut in me thinks at times this was done on purpose by 3rd parties. They knew what they were doing when it came to the Wii. They wanted software interest to die. Why else would they release crap after crap at the risk of going out of business of their HD game flopped in sales. There was a bigger battle to win.
