I've spent a bit of time with Barbara Guest's poetry. There's a bit of preciosity there. I still like enough of it to keep going. I realize that I don't really like the poetry or poetics of Charles Olson. I realize you are supposed to like him, but I just don't respond well to his earnest self-importance. Duncan is also precious, self-indulgent, self-important, etc... I'm not in that camp. I find Zukofsky stiff and uninspiring. I love Creeley's work in many ways, but the part that comes out of Zukofsky and Olson, not so much.
I've defended the language poets. Some are rather dull, though. I'm more interested in the individual talent of those I like than in the group project, based on iffy interpretations of literary theory and linguistics.
A poet I like can write a bad book, or change directions in a way I don't like too much. You almost never find any rigorous critique of poetry from within the avant-garde camp. Everyone is supposed to admire everything the same, it seems. I'm not saying my opinion is the last word, but that the debate almost never happens, except in private.