Have to agree.
If someone were to design a new console targeted at 8-bit retro gaming fans, based upon a 68k or similar 8 bit CPU, etc. and released it in 2012, it would not be an 8th gen console.
But, for the sake of historical records, every bit of new console hardware does have to be categorized as belonging to X generation of hardware, regardless of whether it's up to the minute current, or matured/dated technology. Hence, the Wii will be referenced as belonging to the 7th gen of hardware despite being based upon modestly updated 6th gen hardware specs.
As everyone knows, the real progress of the Wii over the GC was in the user input of the controller, not in the hardware specs of the box itself. Every attempt I've seen to convince anyone otherwise really just needs to look at the end results of the visuals of the games themselves to see the reality of the difference between "7th gen" Wii and 7th gen PS3/Xbox 360.