"GAmecube was marginally better than the PS2?" Give me a break...
While we've become adept at looking at the this generation's gap between the PS360 and the Wii, don't forget that there was a substantial gap between the Xbox/GC and the PS2.
The Gamecube was fathoms more powerful than the PS2, while not to the same extent the PS360 is over the Wii, the appearance between what a PS2 game could do and what a GC game could do was rather stark. Don't try and downplay the gap just because you've gotten cozy with this generations standard.