I'm not sure how to do it otherwise, if not by name. Say, we do call certain web server "nginx" (but probably nobody would object if we'd say "that server by Igor Sysoev et al", it's just quite cumbersome this way), and it probably won't feel right if we'd call it, say, "fastcgi". Yet, for some reason we don't call a certain OS called "GNU" by that name, or author names or any other name at all, but say it like it's a part of other project (of which it isn't part of - here's the problem!).
I don't think it's unreasonable that FSF/GNU Project feel that it's not right. They did a large project, and it had "lost" its name, like their project doesn't exist or is irrelevant. I surely can't speak for GNU Project authors, but I believe, for authors, that may probably feel unfair if not even offensive. I'm not sure what's the "trees" (must be naming) or "forest" (?) here, when they just want their fair share of recognition for something that they did but that's not ever called by its name. Is it really immature?
And, duh, it's not like they're asking something unreasonable or unnecessarily complicated, so, personally for myself, I had decided I have no reasons to not respect this request.
Edit: added about forest/trees - not sure what you meant of those.