And physical goods are already "free" in the Stallman sense, if not patented or subject to restrictive contracts. Both software and hardware have use-value and costs to produce, but only the physical goods have intrinsic market value.
The hammer needs materials and significant per-unit labor as well as intellectual contributions, and in the absence of IP, has market value approaching its intrinsic (use) value. Commercial software that is published rather than used only in-house (i.e., monetized on a licensing model) has market value only because of artificial scarcity, and could hardly exist in a "free market" (without state-enforced monopolies).
Yes, that's right. But what about, say, an electric drill with proprietary schematics? While I may be free to modify the drill as I see fit, it wasn't necessary built for that purpose. Additionally, I can't modify the drill a little bit, and then start producing them myself (I suspect the original manufacturer might have something to say about that).
Perhaps I'm splitting hairs a bit, or thinking too deeply about it, but the topic of tools interests me.
For example, let's say you want to be a carpenter. You would need "open source" tools that you could hack and fix, or you'd have to simply make your own from scratch. I realize such things exist, but you immediately put yourself at a disadvantage because you'll pay significantly more for your tools than a carpenter buying equipment at Home Depot.
Note, too, that I'm not criticizing Stallman's perspective here (I am sympathetic to it)--I'm simply thinking about the ramifications.