Yes that is dumb. As for the multithreading, again it's not really that important unless you have a 4 threads that all need to run at once (this is for a 3 core comparison) Xenon always uses 1/6th of it's power or more for audio, OS takes up processing time too and I'm not sure, but if the i/o doesn't have it's own hardware, then that could blunt Xenon's performance too.
Wii U has separate hardware for all of those things mentioned, so when you compare Wii U to Xenon, it's a bit easier to see why multithreading doesn't matter much, what I haven't guessed at though, is how much more efficient espresso is over broadway, it likely has other advancements that could boost performance as well, one of the reasons I say this is because of the rather large cache the processor has, and as I've pointed out before I really am not sure how important the CPUs are going to be in this next generation, I think most graphical advancements right now are being done in lighting and tessellation, which are both GPU ops.