I had the same thought at first, but reading the whole anecdote made me wonder. It's clear that the mother didn't do what she did just to indulge her own anger

I had the same thought at first, but reading the whole anecdote made me wonder. It's clear that the mother didn't do what she did just to indulge her own anger. She did, in fact, have her son's interests at heart. It was a last resort to get through to him. When you talk about submission as a goal, I think you have to ask, submission to what? If the goal is to get the child to submit to the parent's ego, as it so often is, then I agree with you. But parents have to set limits, and children have to submit to them.