I'm just going to say two different things:
1. Empirical evidence > theoretical assumption. Anybody that has actually played Wii U exclusives would realize that the graphics fidelity far exceed what the PS3 or Xbox 360 have managed, with only the very last games with over seven years of optimizations being comparable.
2. You are attempting to compare things that aren't directly comparable, or at least not without a mathematical formula that would make a high school student cry. If you look back at quotes from chip designers that work with Nintendo, they all say that Nintendo insists on the chips being designed for doing all sorts of weird/unconventional stuff that was simply not the intended use of the components. Plus poorly funded port teams can get Xbox 360 games running on the Wii U with minimal difficulty, meaning that a poorly optimized Wii U game runs as well has a highly optimized Xbox 360 game (hmm...)







