The PS3 and Xbox 360 enjoyed much stronger 3rd party support because industry experts predicted the Wii's failure. This gave it a late start and only now is good 3rd party support showing up. If you want to make a comparison, be my guest but lets do it again in a year and the results may be quite different.
But even those titles you mentioned, Nintendo's own games are absolutly crushing anything else.
Third party support will be stronger in the future, but it's always going to be the Nintendo games that bring in the bigger bucks.