I am not an expert on OTD and frankly nobody knows the “real reason” why kids go OTD.
But if I had to take a guess, something about yiddishkete they hate and it turns them complely off. A simple example is a kid has trouble learning Gemorah , maybe he is dyslexic and the rebbe instead of trying to help the kid. punishes him. Over time the kid begin to hate Learning and gemorah
Maybe the kid is bullied in school , maybe even bullied by a Rebbe’s child and see’s that nothing is done and begins to hate school and hate the yiddishkeite that goes with that school