Poetry, almost by definition, calls attention to its language and form.
In the best fiction, the language itself can become almost invisible.
Part of what we love about poetry is the fact that it seems ancient, that it has an authority of ancient language and ancient form, and that it's timeless, that it reaches back.
It was less a literary thing than a linguistic, philosophical preoccupation... discovering how far you can go with language to create immediate, elementary experience.
The Language Poets are writing only about language itself. The Ashbery poets are writing only about poetry itself. That seems to me a kind of dead end.