Okay, so my citation is, I was there, I was a (fringe) participant in pre-internet piracy culture, starting in 1990.

Pirate BBSes would have various "goods" (in the sense you and GP mean) available for download, including images (hint: some of them may have involve ladies), text files, and software. Sometimes there would also be sections for various art media created by users, such as .mods or ASCII art or poetry or whatever. Those various "goods" would never be all slopped together, they'd be divided into categories. And the category called "warez" would never, ever, have anything in it other than pirated software.

I agree that the s-to-z thing is just classic hacker/leet culture, though it's not internet culture, because it predates the people in question having internet access. I'm saying that the "wares" that becomes "warez" is not "wares-as-in-goods", it's "wares-as-in-softwares". It's pluralized even though "software" is a non-count noun, because then it fits with "files", "images", and so on. And yes, ultimately the "-ware" in "software" is from the sense that you and GP are talking about; I'm saying that the etymology is not directly from there, because otherwise all the other kinds of pirated stuff would also be "warez", and it never, ever, was.

I'm not sure how you are missing it, but hardware and software both etymologically have ware (as in a manufactured article, product, or merchandise) built-in to them. Without ware, there would be no hardware or software, or warez. The root of these words, also silverware, cookware, courseware, Tupperware, Corningware, etc., indeed is "ware." And wares is merely the plural of ware.

I too never seen "warez" used to refer to anything other than pirated software. You make a good point about the derivation; it probably is directly from "software". Adding a superfluous Z to the end of a plural mass noun was also a characteristic of l33tspeak, as I recall.