There are two points here that are being confused.
Point one is that 3rd party games cannot sell on the Wii, this is provably untrue, 3rd party games CAN sell on the Wii in quantities of a million or more. The issue becomes that relative to the amount of Wii games not many 3rd party games do sell well, and, more importantly comes the lead in to point two.
The games that DO sell well on the Wii tend to be crap if they are not made by Nintendo. Looking at some of the million or near million sellers we get carnival games at 2 million, Deca Sports at around 700k, Game party at 1.2 million, High school Musical Sing it at 1 million (kill me now...), Raving Rabids at 1.5 million, raving rabidz 2 at around 1.5 million and Smarty Pantz at 1 million...there is a horrible horrible pattern here. I bet all the games listed cost around 2 million combined to develop.
There are a few bright spots, Resident Evil 4 sold over a million as did one of the lego games (star wars) and then Sonic the rings(or whatever its called) sold about 1.5 million but as far as games that can be considered to have any quality at all (from 3rd parties) that's about it in the million and up set. I guess you can count the olympic games but given the reviews and the featuring of Mario I would put it somewhere between 1st party and the crap section of 3rd party (though at least it did cost more then 100k to make).
Ok yes Guitar Hero has sold well too, but that isn't going to spur any Wii core development, Guitar Hero has sold amazingly on every platform and isn't really related to non rhythm game development. On the other hand Guitar Hero selling well probably did force Rock Band Wii which is good.
The important point though, is that of the success stories on the Wii, almost all of them are low budget crap games and even those that aren't crap are ports of games made for last gen consoles (RE4, Lego, Guitar Hero). The only original Wii game from a 3rd party that has sold well without being a mini game collection, horrific sing along or something similarly terrible has been Sonic and the Secret Rings. Given that most 3rd party companies are not Sega and do not have the one mascot who rivals Mario in popularity, what hope is there for everyone else outside of mini games on the Wii currently?
The Wii is certainly capable of having games that don't suck, Nintendo has made enough of them, but without Rare to save 3rd party support (like it did in the N64 era) things look pretty bleak until people actually start buying games that encourage more good games.
The Wii really needs the conduit or at least SOME quality action game thats not a port from the PS2 to do well. Any game that doesn't have "party" or "sport" in the title would be a good start.
PSN ID: ChosenOne feel free to add me
