You make a good point. You could interpret, "Why would you do that to yourself" as another way of saying "You are self-flagellating" or "What a stupid choice." Or you could hear it as "Why are you studying physics?" You could also say, "What do you mean?" or "Are you saying physics is a bad choice or are you saying you are worried about me for taking such a hard program?" In the workshop I suggest that defence-provoking statements are really poorly worded feeling statements. Like "Why would you do that to yourself?" is just a very bad way of saying "I'm worried about you." or "I'm scared of physics and sciences." or "I'm afraid you are too smart for me." In other words, the criticism is about the critic until and unless you accept it. Your examples are helpful. Thanks.