The issue is simple.
If the Wii version was crushing the others versions, developers could focus on the Wii only and benefit from lower development costs.
As it is they can't and they still have to develop for HD platforms and spend a significant time on game realism and graphics as it is what HD owners want.
As a result the Wii version always look poorer and the lower development costs for Wii does not reduce much the total development costs for developers...
PS : I don't buy the HD consoles owners are more geeky and more into Star Wars.. The Star Wars franchise was actually very present and strong on the game cube... Besides the fact that Star Wars franchise has crossed into mainstream long ago, you have to look a long time to find someone that never heard of Star Wars...
PS3-Xbox360 gap : 1.5 millions and going up in PS3 favor !
PS3-Wii gap : 20 millions and going down !
