I could care less about the terminology people use, but I feel like all your examples would point to the intuitive meaning that "open source" implies. An open

I could care less about the terminology people use, but I feel like all your examples would point to the intuitive meaning that "open source" implies. An open door implies you can see what's behind the door, as opposed to a closed door. An open book implies you can see what's inside a book, as opposed to a closed book. Likewise, open source implies that you can see inside the source code, as opposed to closed source. So I think the claim that it has no obvious literal meaning is a bit hyperbolic, but I get where your thinking, since most developers automatically associate "open source" with "free code".