1) It's my question/answer and I will take reasonable action on it if it stops someone valuable leaving the site
I'm sorry this has caused such consternation. I would prefer to take remedial action than see someone who's made a number of useful contributions leave the beta. We all want this to succeed, and to succeed it needs a wide user base making good contributions.
I'm not sure what action is appropriate in this instance. I would offer to delete the question and/or answer but it seems the majority of users find it helpful or interesting. I don't know if it's possible for me to drop the gained reputation: maybe I could offer it as a bounty on one of your questions?
2) I posted it because asking and answering my own questions is my usual approach to literary questions
When I finish a book that I have enjoyed, it's my usual practice to look up criticism on that book and read around it. If I have particular questions about the book, I will focus my research there.
I read Moby-Dick as an adult (I am not American, and I hadn't twigged it might be a popular study book in the school system) and was fascinated by its structure. I had not read a novel built like that before (although as other commentators have pointed out, there are earlier examples). I had presumed that Melville was writing some sort of historical record: that he wanted to set down how whales were hunted in the age of sail before heavy engineering changed it forever.
On reading some critical essays it became clear that I was mistaken. So, my question is an honest one based on an interest in the book's peculiar structure. And my answer is a distillation of three essays on the subject that I read. I have at least one other self-answered question on the site, which came about by the same process.
That's my motivation. As this is a beta, repeating the questions I could remember asking myself and summarizing what I'd learned seemed a useful way of seeding the site with content.
3) I'm not sure what sort of answers you think it is in the remit of the site to provide
I'm not sure if it's been deleted or not, but at one point you referred to my answer as "sparknotes". I found this a curious criticism because, IMO, that's exactly what the site ought to be aiming at in terms of answers.
Consider. The subject of literature will inevitably attract imprecise questions (something that has not proved problematic on SE sites such as Worldbuilding). These sorts of open questions are probably best answered by exploring the subject at length. But this is a Q&A format in which long essays will make for very poor answers. Therefore it would seem reasonable to expect a good answer to this type of question to be a concise summary of common critical thinking around a subject. And that is exactly what revision notes ought to be.
Perhaps you feel that my answer is too much waffle with insufficient supporting quotes or evidence. I had a quick look at the answers to your questions which you've accepted and it seemed - please excuse me if I'm incorrect - that that was the chief differentiation between those answers and mine. If so, I have a great deal of sympathy with this viewpoint: we should be supporting answers with examples wherever possible. But in the case of Moby-Dick Melville did not leave extensive notes on the composition. And since he is long dead, supposition is the best that we can do.