"...most Linux users tend to just leave the system running indefinitely..."
Really? What planet do they live on, then? Presumably one where energy prices haven't been rising well over the rate of inflation for the last few years, and aren't likely to increase by 50% in the next few years.
Our home computers now get turned off when not in use. At work, this isn't feasible due to the half-hour-to-usable times we have to put up with on our crappy old machines, but as new fast-boot workstations start to come through, I shall be issuing instructions to turn them completely off at night.