1. Sometimes you left an ingredient off or you screwed something up and you just have to sit there and take your lumps.
2. Sometimes they love one thing and hate another.
3. Sometimes it seems like they wanted to critique something. Like I loved the crunchiness but it was a little too crunchy.
4. Sometimes they just wanted you to do something else. They will tell you you should have gone more Greek or should have picked a different cheese. You should have fried it instead of sauteed it. Sometimes they might be right. And look, the judge's feelings are valid. But sometimes the only important part of the feedback is they wanted something else.
5. Sometimes you made a technical error, and because they were watching they spotted the problem and have basically been waiting the whole round to tell you.
6. Sometimes they will start making the critique about you and not the food. They will tell you you didn't respect an ingredient or that you seemed too flustered or too nervous, or basically will talk too much about you and not the food.
7. This is especially true if you are a young chef. Or a female chef. Obviously being critiqued is part of the show. But sometimes, especially in a show that asks you to do something entirely different than the whole rest of your career, you have to accept that very little of what they can tell you will be useful going forward.