I bought the Wii versions of World at War, Modern Warfare, Black Ops, Modern Warfare 3. More than two thirds of my Wii library is third party.
I will buy Need for Speed Most Wanted U when it comes out this month, and the only real reason I haven't bought Black Ops 2 on Wii U is because I don't own the console yet.
Nobody can accuse me of not supporting third parties on Nintendo systems.