Seems to me Pete Gillies is trying to advise those pilots who are likely to kill themselves if they have a real engine failure because they won't act quickly enough. It's obviously most important for students - students need a method, not more "knowledge". Mantra?
The accident reports show it's not only beginners who cock it up, so maybe "knowing" what to do is simply not enough for everybody.
(Note: Airspeed (motion) is kinetic energy not potential energy, as stated above.)