what would you say the reason is about 50% fail enroute then?
From my personal experience (I used to RPO at the academy), book work/worded tests are a very minor portion of grading there. The bulk of the grading is on practical application....Sitting down at the sim and running efficiently. I've known people who are damn sharp, but stumbled on nonradar and radar scenario evals.
Also, when everyone starts the practice scenarios (there's about 40), most people are very lost. About 1-2 weeks into it, and it starts to click in (some) people's minds how everything works. Some people everything "clicks" the day before their eval, and sometimes they pass. Some people, it never fully clicks. Some people, it clicks but they're nerves get to them.
The name "academy" is a little misleading. Not only is it's function to teach, but it's also a weeding out tool. Those trainees need to have the right stuff to go on to a center and train AGAIN, on not only 1 sector, but ~6... For at least the next 2 years.
Facilities don't want to waste time training someone who can't make it, and the more people that facilities wash out, it makes the facilities look at the academy and say, "what are you guys doing? You're sending us shit." So that's why the academy cuts the fat, so ruthlessly.