I think you actually are, in a very real sense. Someone else would have written different lines of codes. The lines of code are a function of yourself, an inherent part of you. Criticizing the lines of code criticizes that part of you. You can’t criticize a novel without implicitly criticizing its author. When we criticize an LLM’s output, we are typically criticizing the LLM. Perceiving criticism of one’s own work as something personal is only natural, and logical.
Now, if the criticism is of a honest mistake, you can learn from that, and own the mistake – show responsibility for it by acknowledging it and correcting it. Of course, that presupposes that you agree that it was a mistake.
Often things aren’t that clear-cut. There can be genuine differences of opinion and of judgement. Of course, one is biased towards one’s own work. It helps to be aware of that bias. It also helps to think in terms of picking your battles.
If you don’t quite agree with a criticism, it can also help to give yourself a chance to change your mind a bit. Maybe later you’ll actually mostly agree with it. And that later changed you isn’t the former you that was criticized. Win-win!