So a glide approach succeeds, if you do it right. A forced landing following an engine failure is also succesful, if you do it right. But which are you more likely to screw up; one out of 1,000 approaches with the engine running, or 0.01 approaches with an engine failure?
Which accident type is more common: Having an accident (no, not
that kind!
) after suffering an engine failure during the approach, or flying oneself into an accident by misjudging the landing, either going off the far end or crashing during a mishandled go around?
If one agrees that landing accidents due to misjudged approaches are much more common than accidents following engine failures during approach, and if one further agrees that a powered approach is easier to judge and control than a glide approach, I think one should limit glide approaches to what is necessary for engine-out proficiency and let powered approaches be the normal procedure.
Which, incidentally, is how I'm being instructed to do it...