DD is a natural auto-didact and likes to figure things out herself when possible. Teaching her to ride a bike was a complete nightmare until I just gave up and stopped talking. I try to stay as hands-off as I can when she is learning a new skill, but sometimes you do need instruction. Helping her with homework is quite a difficult balance. She also loves to fish, but this can be very frustrating for everyone, as the knots, etc are hard for her and adult guidance can be very useful if you want to actually catch something, whch she very much does. At the same time, she really wants to figure it out herself. (She will explicitly tell me this now--"No, don't tell me anything--I want to figure it out.")
My dd6 is exactly this way, too. In piano, she explicitly told me: "Do NOT tell me something's good. Do NOT tell me how to do it." When asked what I should do when I notice her fingering needs correcting, she says, "Tell me later." !! We've had a few go-rounds on this. She's never liked praise-- I think it feels like pressure to her. And criticism while she's practicing seems unfair because she hasn't gotten it right yet.
She reacts appropriately to her piano teacher, though. When he corrects her, she does what he asks without saying anything. But when he praises her, she just nods her head. Sometimes he says, "you're so smart," and she looks over at me, like, "oh, brother."
OP-- You've probably tried this, but I would do a carrot and stick approach. In a calm time, I would tell your son you're concerned about how he over-reacts when people try to coach him. Explain that part of learning is getting pointers, and that he doesn't have to agree with what's said, but he must react appropriately. Then, I would give him examples of appropriate reactions, maybe even trying to be funny about it. I would also outline a consequence. In the case of taekwando, I would tell him that if he can't handle the critiques, he's going to have to quit. Period. Criticism is part of the sport and if he wants to do the sport, he needs to deal with it appropriately. I would make sure to praise him for any progress. But I would follow through on pulling him out.
