Notably, I am unable to find these sorts of arguments (merger of expression and ideas, for example) in Frylock's piece- you know, the kind that would make me take it more seriously. (Weirdly, a commenter even pointed this out to him)
Yeah.
I'm a bit reminded of one of the famous parody cases, 2 Live Crew's case over
Pretty Woman, where the court eventually said "you did not make your case at all, but it happens that you're right, here's why". I think he's failed to make his case coherently, but there's an actual credible argument to be made. I actually got into a bit of a heated argument with Dancey about this on Usenet, back when OGL first showed up, because he was pushing very aggressively the idea that WotC owned the use of the word "Strength" to refer to character stats, and that if someone simply made an adventure that referred to the D&D rules, that might potentially be infringement, and thus they should sign up to the OGL and get permission to use that material in exchange for agreeing not to use the Product Identity stuff. My argument was similar-ish to Frylock's, but I actually tried to argue the case coherently. (Still not a lawyer, though.)
My basic stance is that, in terms of the
intent of copyright law, it seems pretty clear that a module that uses the D&D terminology to refer to the D&D rules, but does not reproduce those rules, and does not use the Named Characters And Settings, is not actually infringing on anything, and is only "derivative" of the stuff that is absolutely not protected -- the rules-as-abstraction, not the text of the rules. And thus, there's no need for anyone to make a special agreement that "entitles" them to make such a thing, and the agreement exists only to fast-talk people into agreeing to arbitrary restrictions, some of which would not apply otherwise, some of which probably would.
That said: If I were gonna make modules, I'd probably go along with it, not because I think it's necessary, but because I think it's socially-desireable for them to say "hey we want to create an environment where people can unambiguously have agreement that they're allowed to do things". It's not about whether they would be
right to sue, or would win the suit, or whether I think they would; having a clear agreement of "we think this is definitely okay and agree that you're allowed to do it" seems like a good thing.