He sounds like the exception, not the rule.
I don't think so. Its a smaller percentage that succeeds in meeting the standard....but that's the case in everything difficult.
IMO, what is important is to not drop your standards for promotion.
The 1st time, Jacob tested he blew all the other candidates away going through the forms, and demonstrating technique....then came the fighting part and during one of the fights he lost his temper......and they failed him for losing control of his emotions. He had to go back 6 months later and re-test again. One of the 1st Dan, complained to Jacob's instructor that she thought they were too tough on him because he was only 10.....in which the instructor pointed out that age is irrelevant.....they grade a 10 year old they same as a 30 year old.