Why did the Gamecube do so poorly? (with respect to sales)

[pbroy]

One_touch_KO said:
For the Topic. Gamecube did poorly because it knew Wii was coming, and got ashamed. That's why PS3 kinda sucks now in sales, the PS4 is germinating and already feels enormous.

 

And 360s are RRODing because the next xbox is coming?