Why should "the leader of the FSF" not make "as many public comments about unrelated matters as Stallman"?

This seems to suggest that a leadership role results or should result, ipso facto, in a reduction of its occupier's freedom of speech.

I don't follow that rationale at all, which isn't to say that I don't acknowledge that such comments can and obviously do in some cases lead to public distraction from the actual work of said leader, shifting the focus to the leader's perceived identity and moral fortitude.

That's a lamentable development to be sure, but to advocate abstention from public discourse as a precaution against the danger of becoming a distraction from the cause you advocate seems to be a clear case of blaming the victim. Stallman is not at fault here.