In the old days the CO or CFI had the power to suspend someone on a 'scrub ride'.
And that was the problem. There was no accountability and although there may have been trainee pilots scrubbed for perceived poor performance there were an equal number scrubbed very late in the course when commonsense dictated a change of instructor should have been the first solution. I recall a typical case where within two weeks from graduation a student was summarily thrown off course for putting a Wirraway on it's nose at the end of it's landing run. The student was blamed for being too harsh on the brakes. It was later discovered the brakes had been poorly serviced and the brake tolerances were quite different from the original specification. The fact that all instructors knew Wirraway brakes were savage, was glossed over. The student training costs must have been substantial so you would have thought the CFI or CO would have taken a closer interest why this particular student was scrubbed.
That sort of scrub mentality was common in RAAF flying training schools simply because no questions were asked and the student was thrown off the base back into civvy life within 48 hours of getting the chop. The fact the poor bastard may not have had a home to go back to was never considered.
I saw this at first hand on many occasions. And this casual attitude by RAAF instructors went completely un-challenged and it cost tax payers plenty. Many scrubbed students went on to make excellent airline pilots.
When I joined the RAAF as a trainee pilot we started at Point Cook. Among the flying instructors at that time were experienced former wartime pilots and three of these were hard-bitten screaming skulls whose reputation for scrubbing students was well known. In later years all three became DCA Examiners of Airmen. A few years back I met up with my former CO of Point Cook. He was a former Catalina pilot during the war and was shot down by the same Japanese units that devasted Pearl Harbour. He was 90 when we had coffee in Sydney together.
When I told him of the fearsome reputation three of his instructor staff had under his command at Point Cook, he was astonished and admitted he had no idea about their reputation. He thought all his instructors were fine gentlemen - after all he was "Sir" to them and treated him with the greatest respect. He was blind to their cruelties to students because no one talked about such things in the Officers Mess.
All instructors whether civilian or military must be reasonably accountable when it comes to teaching people to fly. Some should never be instructors. But I am all for a requirement to first warn students by whatever administrative means is deemed appropriate by the training agency, before a decision is taken to stop further flying training if a civilan flying school - or to scrub a military student. An instructor should not be God when it comes to accountability.