I suspect a real educator might chime in here and trump my answer
. Speaking as a cultural anthropologist, this is all about language and user context. Lesson questions are really a kind of quality control check to see what the student understands. Ancient and honorable MoodleLessonTheory uses some fancy words backed up by mountains of paper. In short the theory says, it is important that students make choices and teachers immediately guide (via jumps and feedback) a student to other areas of understanding based on those choices. The essay question violates this premise, because it leads nowhere in the immediate (as you point out).
However, some use Lesson questions as what I think of as a quiz. In this use, questions are less about the student interacting with the teacher and are more of a message to the student "Please pay attention to the material." The essay question fits into this second, some what controversial theoretical context. Of course some innovators don't worry about these points of view and just figure out what works for them in creating an outstanding learning environment.
As you might tell, the Quiz module is used by our Moodle site as a "Test" (a word heretofore banned in MoodleSpeak), but I will leave that Rose alone for another day.
Thanks for such an entertaining question. Best Chris