The Whale and What it is Not

In the chapter "The Affadavit", Melville steps out of his book and talks to us about its authorship. I will leave to the reader the question of whether this is Melville, Ishmael, or some other voice speaking, but the speaker vouches for the events being told being not just true, but reasonable and not fantastic. Our speaker begs us to neither misunderstand the story or the whale:

For this is one of those disheartening instances where truth requires full as much bolstering as error. So ignorant are most landsmen of some of the plainest and most palpable wonders of the world, that without some hints touching the plain facts, historical and otherwise, of the fishery, they might scout at Moby Dick as a monstrous fable, or still worse and more detestable, a hideous and intolerable allegory.

Please, dear reader, do not mistake the Whale for an Allegory! How quickly these words were forgotten even after the book was re-remembered. Our poor blubbery friend is indeed taken as a hideous and intolerable allegory by all the most sophisticated readers, critics and scholars. Oh sophisticates! Oh learned readers and deep divers! What have you done? Have you become the butt of a grand recursive joke or have you found the treasure hidden behind the false clue?! How can this poor not-allegory possibly bear all the meaning to which you've attributed it?