It always strikes me as odd to see those two referred to as OD&D, as they seem fairly different from it to me.
It always strikes me as odd that this changed.
When I was a kid, there was OD&D and AD&D, and OD&D was the name we used for all the stuff that wasn't AD&D, which included BXCMI/RC. If someone said, "Hey, let's play OD&D," the "O" more or less meant "not-Advanced." It didn't mean "the original rules from 1974," it meant "
the original D&D game," i.e., the TSR game-line that
included the 3LBB, Holmes, Moldvay/Cook, Mentzer, and 1070/RC/1106 editions.
That the rules had changed from edition to edition didn't really enter into it. After all, if pre-UA 1e and post-Skills & Powers 2e can both still be AD&D despite the wide mechanical gulf between them, it's not so hard to grasp that 3LBB and RC can both fall under the OD&D umbrella.
And apart from some discussion on rec.games.frp.dnd back in the 90s advocating for calling BX and later "BD&D" instead of "OD&D," I can't really find any evidence that anyone had a problem with this broad use of OD&D until Dragonsfoot in the early 2000s. (Though it wouldn't surprise me at all if was actually the K&K Alehouse that ultimately instigated the change, on the tenuous grounds that Moldvay and later aren't sufficiently "Gygaxian.")