In article , New Guy wrote:
Does anyone have any theory as to who is responsible for these
anti-brand-name postings?

Yes: you are. This one, at least. I didn't see it, and never would have, if
you hadn't reposted it.

Who would have a reason to post this material periodically on usenet?

You tell me.

Is someone getting paid by generic product makers to put the word out
that generic products are just as good, if not cheaper, than brand-name
counterparts?

I imagine. How much they paying you, anyway, to repost the spam posts after
they're cancelled by the ISPs?