I think they lack the motivation to really push the hardware to the limits. Why spend so much effort making say, The Conduit, for Wii when any garden variety HD game will look better? The Xbox was a very powerful piece of hardware comparably, and people wanted to show it off; the Wii is not.
"Now, a fun game should always be easy to understand - you should be able to take one look at it and know what you have to do straight away. It should be so well constructed that you can tell at a glance what your goal is and, even if you don’t succeed, you’ll blame yourself rather than the game. Moreover, the people standing around watching the game have also got to be able to enjoy it." - Shiggy







