Every game developer, if it wants to create art, uses in the best way the tools he has for it. The game itself can be a masterpiece or a piece of crap and that has nothing to do with the power of the console. If that was true, then a game made today for the Wii or for the PS2 like God of War 2 could never pass the 8/10 mark, because it could never reach the graphic level of some crappy game made for the 360/ps3.
Saying the developers are limited by the wii is nonsense, because they are always limited. They are limited by resolution, interfaces, support, time and money.