Just a reminder that Linus was inspired by the existence of Minix and by the GPL. So RMS had an important influence on Linux's success. "Influence" =/= "role", but is generally (and in this case) a "part".
None of this justifies the dogged pursuit of the "GNU/Linux" nonsense , but I do think this is an important clarification.
BTW apart from RMS himself I've never heard a single person refer to "GNU/Linux" except in a joking fashion, and I hang out with a bunch of people you'd think would, if anyone took it seriously.