Don't forget that Rockstar/Take Two released Manhunt 2 and Bully: Scholarship edition on the Wii, which were both miserable flops. Now Manhunt 2 was a really bad game and it didn't sell well on any of the platforms, but Bully was a pretty good game and it sold well on the 360 despite both consoles having comparable userbases. And let's not forget Table Tennis, which sold about 100k on the Wii. Now it could be undertracked or missing data, but that's still a heck of a lot less than the 360 version.
Nintendo fans have never had a GTA game on their platforms, and many object to it now as the treacherous captain of HD gaming and especially the last generation. GTA4 has an entire physics system and environment build around an engine that I don't even think the Wii can use. If it can, can the Wii honestly handle the environments in the game? It's pretty big, and it still has lots of freezing and framerate drops. And yes, it could get a giant graphical downgrade, but do you really want that?
