The problem with the Wii is, it was not released first, nor was it a successor to a highly popular console.
The NES basically started it's generation, it got the 3rd party support because it was huge before anything else had a chance.
The SNESwasn't first to the market of the generation, but it was following from the NES, and even though it was following the NES, the MegaDrive made a damn good run for number 1 (50 million SNES to 30 million MegaDrive is hardly domination)
The PS1 was first to the market, and built up third party support (helped by the cheap CD based games and Sony's "everybody in" policy, unlike Nintendo who were restrictive, which helped stop shovelware but was still a restriction that the PS1 didn't have)
The PS2 was also first to the market (well Dreamcast was but wasn't any real competition) and was following the succesful PS1.
The Wii was not first (in fact it was last by 2-3 weeks) and is following the GameCube.
