I am interested in whose class you took, as I am a CCW instructor in that area.
We have an extremely high pass rate as well. On those who have a demonstrated inability to hit the target at all, we attempt to correct their shooting technique. If they show rapid improvement, we usually call it good. Once it was a mechanical problem- a guy had aftermarket sights on a Taurus Millenium, and the front sight was way short.
There have been a couple cases where despite repeated individual coaching, a person was unable to hit the target. We issue them a conditional certificate pending another range trip with improvement.
The only case in which we would flat out refuse to issue a completion certificate is repeated negligent gun handling.