I think one could make an analogy with cars. A large fraction of efficency gains have been "lost" to accessories like power windows, additional electronics in the car, etc. A lot of fuel efficency gains could be realized by selling cars with fewer options. But car makers are unlikely to want to sell those (they make more money off the options) and consumers as a whole haven't seemed to demand them.<p>Also, it appears this post is ~4 years old, but I think the point is still relevant. (Last year, I switched from GNOME to xfce and was quite happy with the reduction in the amount of cpu cycles going towards silly window minimization animations and the like).