So the only bone of contention is when you actually close the throttle - surely that depends on your approach angle and airspeed.
If you have the correct angle and airspeed - shallow = more power and steeper = less - then you will still want to close the throttle just before you flare, regardless.
The idea of holding power on all the way to the ground is anathema to most people's idea of correct technique.
A glide approach is just a steeper version - not by much - and works on microlights and heavier aircraft so what is the issue?
No-one is advocating closing the throttle at 50' as a practice - you use the throttle for as long as you need to to maintain the approach angle but you still close it before you flare.