What does a whale represent to us? In the 1850's the whale was a leviathan, a creature of massive proportions that inhabited a hidden universe and provided products of beauty and necessity (oil and ambergris). For us, it's one more being in danger of extinction that "sings" and is part of a controlled world that holds little mystery. Imagine confronting this huge being with small boats and harpoons.
Two elements make Moby Dick subversive. For the reader to understand the novel, Melville provides all the possible background information available to him in his day. From a treatsie on the color white across cultures to classification and anatomy of the whale, this novel educates the reader. And all of this requires DESCRIPTION and Melville is a master.
Description has fallen out of favor. Writers are routinely instructed to eliminate adverbs and all excess words. Are we all victims of Hemingway's terse prose? Or is it a lack of attention span? Take the 6 word story as an example. 6 words are used to express an entire story and there are contests to do this. Yes, it can be done. But why? We have a glorious vocabulary in English, one I particularly appreciate since English wasn't my first language. A literary magazine I recently contacted now only publishes flash fiction. Is this the path literature is taking?
The other subversion is that man is not the measure of all things as we've been led to believe. What I liked best about Moby Dick was the ending. Despite all foreshadowing and warnings, I was surprises by the ending. Decades of the perfect Walt Disney type ending left me aghast and then thrilled by the last line of this novel.