the implication that any popular piece of libre software owes anything to Stallman by the mere virtue of being libre is totally wrong.

Considering Linux: Linux was proprietary at first, until Torvalds was inspired by the free software movement to free it, even using GNU's GPL. He later said that making Linux open source was the best decision he ever made, and I'm pretty sure that this would not have happened without the popularity of GNU and the movement reaching him. Linux would've been just another small proprietary kernel. So Torvalds owes a lot to Stallman.

Also, without GNU, Linux would not have been practically usable. Only after the hard work of combining Linux with the already huge codebase of GNU could Linux be meaningfully used and become popular.

In fact, Stallman's version of "open" is deeply intertwined with the American version of what it means to be "free" politically

Well, "open source" gives you exactly the same freedoms as "free software" gives you, so proponents of "open source" can't be that far off ideologically.

it has manifested so many times that there are several open projects with the entire goal of not using GNU components, code or licenses.

The code is already there and it's usable. Not using it because you don't like the person/organization seems a bit... misguided.