The idea that you are writing for a community in order to create value for them is right, and that you do that by pointing to some anomaly in the constitution of the field is also right. His notion of what constitutes an academic community is also largely right, but he doesn't seem to think there is anything like "knowledge"--just what gets deemed knowledge by those with the power to do so. He's almost where David Bartholomae was 40 years ago. He's a neopragmatist rhetorician so he doesn't see writing as a form of inquiry and learning. He says he works with experts, who only need help presenting the ideas and knowledge they already have, so he doesn't have to deal with the question of how you come up with the ideas and knowledge that make it possible for you to ask where a productive site of inquiry into the community is. So, he sneaks back in the liberal, entrepreneurial subject he seemed to dismiss at the beginning.
Also, you can't really complain about writers "interfering" with the reader's reading process if you also want to create "instability" for the reader. He actually seems to suggest at the beginning that it's a problem if your reader has to reread your text, which is ludicrous. What you really want is people arguing over your text--despite his criticism of thinking in terms of the individual writer thinking internally, that's the way he talks about the reader--as looking for value for himself. You read something because other people are reading it and you need to argue with them about it. How else would you know what to read? Does he really think someone can read two paragraphs of Baudrillard, Derrida, Foucault, etc., and say, "nope, that's enough--no value in this for me." That's a pretty sure way to exclude yourself from the community. Once people are arguing over your text they are rereading it many times. Its value can't be evident at first glance. But, he's honest about the limitations of what he's doing--it's a kind of professional consulting for academics who want to publish in academic journals.