They care as much as Nvidia does.
The roles currently seem the reverse of what they were when that video came out however. Back then you had the GTX480 which for its time used lots of power while AMD had the 5870 which was comparable in performance and was 1,5 times as powerefficient on the same process.
AMD back then made use of the situation by producing that video. This time around Nvidia seems to refrain from stuff like that however, while also lowering the prices of their card way more than they'd have to based on product positioning and demand.
All nVidia has done is throw out the double precision floating point circuitry in their chips. It's not magic or rocket science. Their lower power consumption is the direct result of cutting out a feature. Whether that feature is important to you or not is your decision, but that's how they've done it. They aren't smarter than AMD, they're certainly not wizzards. AMD can do exactly the same thing if they want, and frankly, I wish they would, as I would still buy a gaming card based on such a chip, since I don't use double precision floating point in any applications I use.
Much like a car company pulling out the rear passenger seat in their latest car model, and then advertising that it's 'even lighter, gets better fuel economy!' there's no mystery behind how they did it.