What don't you get there? IF XBox 3 is 6x as powerful as 360 (which is not my suggestion but his) and WiiU is 3x as powerful as 360 then XBox 3 would be 2x as powerful as WiiU.
But my point is all these 'thumbnail mathematics' (2x power to the third power) just don't work in any sort of solid argument.
In practical terms what multiples of power is the 360 to the original Xbox? A console can really only be defined by the other consoles/platforms that exist on the market at the time.
So we know that the PS360 are much more powerful than the Wii. That's a fact.
And we know that the WiiU isn't a generational leap forward and thus isn't much more powerful than PS360. Certainly the gap between them isn't as big as the gap between the original Wii and the PS360.
It just makes more sense to me when we talk in this broad, yet ultimately more accurate, terms.