That doesn’t mean anyone should stop doing literary criticism any more than forgoing fiction. Naturalism treats both as fun, but neither as knowledge.
What naturalists really fear is not becoming dogmatic or giving up the scientific spirit. It’s the threat that the science will end up showing that much of what we cherish as meaningful in human life is illusory.
Not a particularly surprising view coming from a man who has written twelve books on the philosophy of biology and economics. The part that I find most telling is his term "illusory." Yes, a scientist (or naturalist) would view much of what we "cherish" (hope, faith, love, friendship, ethics, values, a.k.a. everything literature is about) as not knowable via science. How can we scientifically prove any of that? We can't, which can't be a comfortable position for a man of science.