Bob, I see where George is going and I tend to agree with the sentiment. From what Tom is saying, Wisconsin does too. Load diversity in residential circuits does make a lot of this derating somewhat moot. If you really had 20 fully loaded 20a circuits, the 2 ga al service conductors would burn up.
All this said your point is still valid.
We have to go to war with the code we have not the code we wish we had.
