Third party titles not selling on the Wii is a gaming urban myth. There are plenty of titles that have earnt publishers a profit - Mario and Sonic, Just Dance, Red Steel, Red Steel 2, Resident Evil 4 Wii Edition, Resident Evil Umbrella Chronicles, Resident Evil Darkside Chronicles, Monster Hunter Tri, House of The Dead 2 and 3, House of The Dead Overkill, Tatsunoku Vs Capcom, Tiger Woods PGA Tour, FIFA (even though it's seriously gimped on the Wii), Muramasa Demon Blade, the Trauma Center games and Madworld spring to mind.
As Ubisoft and Sega are going to find out with ZombiU and Aliens Colonial Marines respectively, if a publisher puts effort into a game for a Nintendo console and - most importantly - markets it properly it'll sell. It's really not rocket science. The majority of those titles I listed above get a A for effort but a B-D for marketing and they all either met or exceeded expectations.
Have a look at the Wii titles that've sold over 500K and compare it to the amount of PS3 and 360 titles that have sold the same, even if you ignore the fact that PS3 and 360 development is more expensive there's a shitload more Wii titles that have gone gold compared to PS3 and 360 titles. The 'third party titles don't sell on Nintendo consoles' excuse may have been valid with the N64 and Gamecube at times but nowadays it's an urban myth that some people in the industry can't shake, and probably won't shake until the 'hardcore' launch and launch window titles for the U sell like hotcakes. And when (there is no 'if' about it) that happens there are going to be more than a few executives kicking themselves for not supporting the U right out of the gate when Ubisoft have money coming out of their ears.