You can substitute the PS2 for any other console. No console reached its performance so soon in its lifespan, what makes you think the 360 is so simple in comparison to any other console? Parallel processing in games is a new approach for all systems, including PCs, so every platform is currently suffering because of it and not reaching their potential (bar the Wii of course).
It's about degrees. Relatively speaking, there is nowhere near as much untapped power in the 360 as the ps3. The 360 has been lead platform for years now and has received massive investment in time and resources, not to mention the fact that it is a general purpose architecture and thus requires little or no change in development approach. The ps3 is a different kind of machine and has had relatively little investment compared to the 360.
So, are you going to ask me again "what makes you think the 360 is so simple in comparison to any other console". Have I not answered that question 4 times in this thread already? Perhaps you could tell us why you think the latent power of the 360 is still untapped?