I can see how giving students multiple tries would be a great teaching aid if we had human-level AI. With what we have now, I'd bet it's just training them to

I can see how giving students multiple tries would be a great teaching aid if we had human-level AI. With what we have now, I'd bet it's just training them to produce essays that hit the flaws in the AI as hard as possible to produce unreadable garbage with high scores. 20 tries per essay adds up to a lot across 12 years of schooling. Teachers are extremely overworked, underpaid, and underappreciated. I'm not surprised that it was easy to convince them to offload the difficult and time-consuming work of manually grading essays. This also means they don't have to deal with complaints about unfair grading. A machine did it and it's out of their hands.