If anything, the fact that the Gamecube's graphical superiority didn't help it much in the market is what made Nintendo make their shift towards innovations instead of clock cycles.
You can't have both because the market has told Nintendo specifically (via the DS, 3DS, and Wii) that it wants unique experiences, not more pixels.
Well, then Nintendo really learned the wrong lesson from the Gamecube versus the PS2, because the lesson should have been "people want to be able to play DVDs on something that costs that much and hooks up to your TV, and they don't like switching discs to play a game."
https://www.youtube.com/watch?v=KkKX-nU9fX4
If anything, the fact that the Gamecube's graphical superiority didn't help it much in the market is what made Nintendo make their shift towards innovations instead of clock cycles.
You can't have both because the market has told Nintendo specifically (via the DS, 3DS, and Wii) that it wants unique experiences, not more pixels.