The validity of any theory of poetry rests in how well it works in actual poems, not in how well turned the theoretical phrasing is.
There should be an absolute minimum of poems about poetry; poets, regardless of politics or aesthetic preference , really need to turn their language skills to the world and not onto themselves or their craft. Poems about poems , for me, is analogous to building cars from the spare parts of old cars--the enterprise will just collapse under it's own conceited laziness unless something fresh, alien and external , from outside the poet's subjective being and his or her ingrained habits of rhetoric, that would challenge the given assumptions a habit of phrasing would other wise lead a poet to rest upon. The poem is a vehicle to engage reality, not to wish it away with an obsession with it's own form.
Difficult poems are not to be discounted merely because they're difficult. There are poets who layer their works in ways that reward the effort to understand them on their own terms. There are things that cannot really be written about simply, and require genius to have the language extended to the point that a carnivalization of our paradigm can be contained with the word systems we were born with--Louis Zukofsky, Charles Olson come to mind.
Clear, concise, "objectively" coherent poems are not to be discounted merely because they make sense to the reader in more conventional ways. There's quite a bit of complaining about the "School of Quietude" that dominates poetry awards, and for the most part I share the disdain--faux confessional bits of inconsequential meditation that does not arise above a listing of wistfully arranged images and an implied, defeated sign, all in the moment. It's off putting and it's a cheat on the craft. But there poets who can compose the lyric that can bring a number of ideas , images, bits of memory to a single moment, a synthesis perfectly realized, truthfully told, without verbal padding. I think of Thomas Lux, my friend Peter Dragin, Paul Dresman, Kate Watson. This is not to say that these smaller poems are the only things these writers compose, far from it. But the smaller ones, about smaller things, should be respected when the near perfections are created
An absolute minimum of literary language and reference; excessive reference to other writers , philosophers, and the like makes me think that someone is hiding their college syllabi and hasn't yet learned to write honestly about their experience. Other writers should be the models, not the frameworks of what a younger poet writes.