@picko - I do understand your point and I was addressing it in a different manner. The "casual" crowd doesn't go out and buy many games. They are happy with Wii Sports, Wii Play, Carnival Games, Raving Rabbids and Wii Fit. THey probably will go out and get Mario Kart also. Putting out clones of these games and other mini games is a well that dries up quickly. 3rd party developers will find that harsh reality soon enough. They need to start making gateway games - games that take those casual gamers and start challenging them a little more, bringing them to the more serious game level. Some already have advanced, playing Mario Galaxy and whatnot. This is a big step from just bowling for 10 minutes into playing out a full game.
If a developer puts out a full AAA title, they'll put out a million or so copies. Considering that Wii games take an average of 5 million to make on the high end, a good AAA title would stand to make that developer around 20 mil+. Compare that to the average PETZ game, which might take a mil or 2 to make, but only sells 100k. They might make 2 mil plus, thus barely breaking even.
So the point is, there is a great reason to develop AAA games on the Wii - profit.