As a testing company, maybe I would advise the teacher to give a discretionary, external reward for creativity, and maybe provide an advanced lecture for those inquiring students, but for policy reasons, people just want to know if students understood the content to measure pedagogical policy. You can either ask students to write an essay (unscalable and contingent on other skills), or you could ask a question with true and false answers.

Otherwise we cannot measure the efficacy of pedagogical policy.

He asked them to do that, since that is the right thing to do where a textual question can have multiple answers depending on the context; however they refused to do so.