Looking at North American sales for the Super Ninendo, Nintendo 64, and GameCube, I can see why there was still a lot of avid Nintendo fans during much of the last decade:
Super Nintendo: 23.36 million
Nintendo 64: 20.63 million
GameCube 12.94 million
There was only a slight dip from the SNES to the N64 in North America in sales, while from N64 to GameCube they lost 7.5 million sales.
Due how well the PS2 did relative to the GameCube in North America, I think that's the reason why there seems to be so much Sony fanboyism in video game communities nowadays (I think many of the people who grew up on the NES and SNES are no longer active on video game communities, and that some of people who grew up on the N64 are starting to leave).