Oh come on... I am a Wii only owner... I love my console of choice. It has great games and so on.. , but I am sick & tired of devs and publishers complaining about their games not selling on the Wii. Quit whining please.
I played TC for some time, it did not interest me at all. You're asking, why exactly Overkill did not sell in the millions like the 2&3 did? Overkill was a full priced game, while 2&3 was $30 from the very beginning. Yes it's that simple.
Madworld on the other hand, gosh, it was fun, but Sega gave us europeans the short end of the stick... Two black bars? Why not full widescreen. S**k it.
As s.b else wrote COD: WAS sold aroun 1.3 million and continues to sell, and
COD:MWR is already at around 400k, only thanks to the word of mouth ( and because it's call of duty ) There was no marketing for Reflex.
So quit whining and start making some effort on the Wii, put some good marketing and miracles will happen, believe me.