Just because the console is in the most homes doesn't mean it's going to be the most profitable for you. EA's thought that it would be a train full of money coming in with their titles appearing on the Nintendo console but things haven't turned out so well
While it has the largest install base, a lot of those are in Japan and Asia where Western companies have a hard time producing a profit. I've yet to play any third party game on the Wii myself and I barely play any first party titles as the interest on those tail off pretty quickly for me. That's not to say that there's nothing good on the system but I'm a little sad I can't find anything that I can sit down with for long periods of time like I do with the PS3 and 360.