Most laser printers consume several hundred watts while idle in order to keep the fuser warm. A few models shut down automatically after a while, and this feature seems to be the wave of the future.
Wear-and-tear due to power cycling is no longer the problem it once was. The advice in the FAQ would have been appropriate in the 1970s, but no longer. A good modern rule of thumb is to turn off electronic equipment if it won't be used for a few hours (overnight or weekends), otherwise to leave it on.