What's Wrong with a Little Symbolism?

I finished reading Nathaniel Philbrick's Why Read Moby Dick? recently. It's a slim volume of only about 130 pages that provides some historical, biographical, and analytical details on the great American novel. It was fascinating to hear about Melville's relationship with Hawthorne (the author's namesake), real-life accounts that Moby Dick was based upon, Melville's real-life experiences on a whaling ship, and details about the historical Nantucket. Melville came to Shakespeare late in life and virtually rewrote the entire novel after having completed a first draft to give its characters more "Shakespearean" weight. Philbrick also discusses the novel's Biblical style; its sentences and rhythms are epic and breathtaking. Why Read Moby Dick? drips with Philbrick's enthusiasm for what many call the greatest American novel. He came to the novel in high school, and while he admits that most of his peers did not take to it well, reading it for him was a deeply meaningful and life-changing experience, and he claims he's now read it thirteen times.

One thing, though, that annoyed me slightly about the book was Philbrick's insistence that Moby Dick doesn't symbolize anything. His point is that the whale and the story as a whole suffers from attempts to put it neatly into categories: the whale represents God, the whale represents the power of Nature, etc. He feels that thinking of the whale as a symbol takes away from the fully realized complexity of the creature. It seems like this is something I've been hearing quite a bit about lately from lots of different places. (And by lately I mean the last 20 years). College professors, some English teachers, and writers like Philbrick have something against symbolism. I've heard lots of people who want to downplay the role of symbolism. Now, I see Philbrick's point and I would agree with him if was an either/or possibility. And there are certainly works whose characters are clearly meant to be symbolic and that heavy symbolism flattens the character. They become types not people. Some might say this is the case in, say, Animal Farm, and if we compare Orwell's characters to, say, Jane Austen's anti-symbolic and fully realized characters in Pride and Prejudice, we might all see the point. But I don't understand why people like Philbrick can't see the option that Moby Dick could be a symbol and a fully realized character. Maybe I'm just naive and don't understand how this all works. I see the complexity and richness of the whale and Ahab's character, but I also think they mean something beyond the literal.