The prompt is the ground truth that reveals the assumptions and understandings of the person who generated the code.

It makes a lot more sense to review and workshop that into a better prompt than to refactor the derived code when there are foundational problems with the prompt.

Also, we do do this for human-generated code. It's just a far more tedious process of detective work since you often have to go the opposite direction and derive someone's understanding from the code. Especially for low effort PRs.

Ideally every PR would come with an intro that sells the PR and explains the high level approach. That way you can review the code with someone's objectives in mind, and you know when deviations from the objective are incidental bugs rather than misunderstandings.