i guess it would have to do with a difference in view points. for example I could care less about using an extra 100 watts to play old games (i own a 480 after all haha) also I have noticed that when monitoring my GPU usage in games old and even some newer ones it is very rare that I am using 100% of my GPU while gaming most older games on use 30% of my GPU thus my temps are much lower then when i am at 100% and same with my power usage anyways.
gpu usage is a useless metric to correlate to power consumption. Far Cry 2 used to show 100% constant usage, while crysis jumped around 70-95 percent while temps playing crysis were much higher.