WOW- What a lousy story. And you are right that people do push the kids away but I think there is another half to that story. Those people are not the majority and they are idiots. What often pushes the kids away (from what I personally have been told) is the response others have to those idiots. For example, when a teacher batters a kid emotionally and the parents write it off or let it go, telling the child he should be quiet and be respectful, that puts the seal of approval on the teachers behavior. When parents go the route YOU took – being incensed, running to the park to find the man, going to the man’s house and approaching your Rav – you are then giving your child the message that this man is NOT a Torah Jew. This man is an idiot and you will not tolerate this behavior. There are many parents who would NEVER push their kids away, but whom never put in “enough” efforts validating the injustice or preventing them from repeated pain.
SO GOOD FOR YOU! And may this be a zchus for both that son and all your others.