[noch]

> [T]eachers should only be teaching works of literature that have one and only one objectively correct interpretation, like the Bible.

That's a non-sequitur. What they are saying is that: "if a text can mean anything, then by definition it means nothing."

Not coincidentally, this nothingness is part of the postmodernist project of "destabilizing meaning" which is in direct opposition to, as a rejection of, the progress of technology and science, which instead seeks to discover empirically what things are and what the truth is.