It seems as though you are thinking of "essays" in the College sense of the word in that they are to be strictly structured and meeting certain guidelines for quality, but I don't think that is what is intended. To me, writing is easy and I enjoy it, but other people do not find that to be the case for them and they are still able to write their "essays". I think that the point is not to have someone explain something exactly the way it was taught, but explain how they interpret it and what their take on it is--that, to me, is proof of knowledge. As I mentioned previously, this can all be done verbally by asking someone in class to explain something. For instance, if you were to ask someone in class what all of the applications of a middle block in a given kata might be they might give an answer of "blocking a punch to the midsection", if they sit down and think about it and write about it they might come up with "blocking a punch to the midsection, or blocking and breaking the attacker's arm, or deflecting a grab and applying a wrist lock, etc.". To me, the writing itself is not to be judged, but the thought process behind it because writing is a tool to provoke thought in both the person reading it AND the person writing it. Just my thoughts on the subject.