Mmm… I sort of take your point, but I don’t think I agree. There was certainly a mode of “publishing” that evolved with Usenet, and there were certainly authors who made public substantive pieces of writing through it. But — perhaps this is my I-never-really-got-Usenet bias speaking — the Usenet groups were such a sea of voices that it seems to me to become hard to distinguish one piece of writing from another. Yes, it had a net-native rhetorical mode, but I’m not talking about the rhetoric of authorship. I’m talking about the production of a text that is in some sense “finished” — in the world of the codex, the printed-and-bound; in the world of the blog, the post. The machinery that transforms the author’s text into a product.
This argument may be a bit beside the point, though. In fact, I think the way out of the bind that you point to is really neither A nor B, but C) change “net-native” to “web-native.”