I don't think it's a matter of excusing, it's whether he has ultimate authority based on the fact that he created glibc and he's the head of GNU. Talking about excusing assumes he did something wrong, which is jumping the gun, since that's exactly what's being discussed.
I have a hard time seeing where he did something right here. He is behaving like a petulant child because people didn't find his joke funny two decades later.
He is the "boss". No doubt about it, he is the copyright holder, everyone working on the project has surrendered copyright over to him. I've got my strong reservations on BDFLs and the way their egos get stroked, but it is what it is.
But he is not a "leader". Because a leader does not cut the legs out from under the people he delegates to run things. He has every right to insist that GNU maintains his dumb joke... and everyone who's put in all of the hard work and effort into the project over these more recent years has the absolute right to leave over it.
If RMS wasn't the project lead, but any other maintainer, then his behavior of making such a big fuss about this particular thing (which, very importantly, _is not a very important thing!_), against the consensus of many other maintainers, is something.
If he were on the same level as other people, this behavior wouldn't be accepted. So the question then becomes:
Does the fact that he's "the boss" excuse his behavior of fighting against the consensus on an issue of this level of importance?
