...another contribution to the Harriet comment-burble...
In the course of your argument here, you assert three points which are pretty close to truisms, but which I also agree with : 1) the NAP anthology has been credited with a political "progressivism" which was not really so advanced; 2) politics and aesthetics are not equatable, even in one & the same artist; 3) negativity for its own sake is pointless, & worse.
Nevertheless, these points don't seem to really address the crux of the position laid out by A. Mlinko and others in previous posts etc. In order to grasp what this position is, one has to be willing to acknowledge a gray area, between art and politics. Let's provisionally designate this as "cultural politics". Keeping in mind the tradiitonal notions of the role of poetry as not only an art form but also a didactic act, a form of education (cf. Milton, Dante, Sidney, etc. etc. - let's compare this role loosely to the idea of "applied science". Whenever scientific theory & discovery are applied in the real world, there are consequences in the realm of "cultural politics" (the forms of action and interaction in which a cultural engages). This same function applies, perhaps to a lesser extent, in the realm of the arts. Artistic creation has social consequences.
Here is Wallace Stevens ("Of Modern Poetry"):
It has to be living, to learn the speech of the place.
It has to face the men of the time and to meet
The women of the time. It has to think about war
And it has to find what will suffice. It has
To construct a new stage. It has to be on that stage. . .
If we take Stevens seriously, we have to think of poetry as in some respect an embodied, performative, and rhetorical art form. The aesthetic form of the poem does not, contra the New Critics, reside in a self-contained textual receptacle. The form of the poem achieves its realization, its actuality, in some form of social (& perhaps actual) "stage".
I would call this gray area, generally, the sphere of cultural politics. The space of social dialogue and shared language, where, in Stevens' words, "the imagination's latin" is compounded with "the lingua franca et jocundissima".
Using this concept of the "gray area" as context, let's look again at A. Mlinko's argument, which was, at least in part, to point up a historical contrast between the social-professional matrix of poetry today and that of 50 years ago, with the NAP anthology as emblematic of that difference.
I would, again, support that general perspective - since I think the aesthetic choices of the NAP poets did indeed put them "outside" the sphere of what was considered the normative discourse of traditional poetry at that time; and that one of the signal motives for this direction lay in the poets' desire to "learn the speech of the place", to "face the men" and "meet the women" of the time, to "construct a new stage".
And I think this does have to be contrasted with the contemporary situation, of which perhaps your own position is a pretty good exemple : the assumption is that poetry is self-sufficient and somewhat detached from politics, simply because the high level of professionalism supposedly structuring the field allows its practitioners to absorb and comprehend both social theory and all forms of technical innovation - so that such notions as "outside" or "avant-garde" become irrelevant. Stevens' position, in contrast, emphasizes a very high level of contingency in the poetic process, since the poem does not actually achieve its form, its aesthetic actuality, until it has been in some sense "enacted" in the public sphere. And we are not talking about the public sphere of the university or the profession, here, but of the sphere of "the people" of "the time". Outside, in the big outside."