My point was merely that you can still gain insights when reading the more modern literary criticism and theory by keeping an open mind and using your instincts as to what 'makes sense' or intuitively 'rings true' whilst at the same time understanding some of the underlying politics that may be driving the particular argument. In other words don't adopt the herd mentality.
Good luck with that, since inculcating a herd mentality is exactly what a lot of such teaching seems to be about.
As for detecting what makes sense or rings true: if someone is really well read in the primary works, he or she may be able to sift some insights from a mass of dross; but how many college students are well read? I think it is a travesty that undergrads, in particular, should be required to read the theorists, when the fact is that they have have read only a few of the great works. Just when are they supposed to read the Bible, Gilgamesh, Homer, Herodotus, Sophocles, Aeschylus, Aristophanes, Euripides, Ovid, Lucretius, Virgil, Apuleius, Augustine, Boethius, Beowulf, the Edda, Dante, Chaucer (Canterbury Tales, Troilus and Cressida), Sir Gawain and the Green Knight, the Saga of the Volsungs, Grail romances, mystery plays, Shakespeare*, Marlowe, Webster, Milton, George Herbert, Thomas Traherne, and a host of great writers of the succeeding 350 years? Or even half of these? On their own time? Does that seem like too much ancient and medieval? All right, what would you cut and why? .... Instead they read a relatively few classic works (perhaps including, as one colleague noted,
Beloved in three different courses) and Barthes, Lacan, Derrida, Kristeva, Foucault, and/or their epigones -- ?
I teach, in part, for the future. I sincerely do not believe that, thirty years from now, my students will be saying: "Why did I read all that Shakespeare, Dickens, etc. in Prof. ----'s classes?" But I think some students, thirty years later, will feel they were cheated when they spent so much time on.... well, you can imagine.
*At least (off the top of my head) they should read The Taming of the Shrew, The Merchant of Venice, As You Like It, Twelfth Night, Measure for Measure, Hamlet, Othello, Macbeth, King Lear, Julius Caesar, Antony and Cleopatra, Winter's Tale, Tempest, 1 Henry IV, some of the Sonnets... I ask: What could be more worth their time than these?