Say one thing, do another...

Yes, I believe that those people *say* that.

But when they're in the shop, they'll make their decision based on price, physical attractiveness (shiny, silver, small), brand reputation and advertising recall.

There are already plenty of more environmentally-friendly (i.e. lower-power) PCs out there, and a few seconds with Google will find them, but they make up only a tiny percentage of sales because they lack the edge on price, silver-shinyness and brand reputation.