Obviously not but if you watch the video, the Commandant cites that as being the reason and a number of news pieces talking about women in combat all use that same argument and it does make sense (can send you links to female reporters saying the same thing in their new clips) . It isn't about making rank (used the wrong term, my apologies) but if you want to hold many a command position, you have to have held command at a lower rank, in a combat unit. General Barrow did not become the USMC Commandant without having held command in three wars. The Army is even less centered around infantry than the Marines ever will be, and even then, primarily our forces consist of a damn large number of maneuver units. So if your wickets to the high echelons are, PL, CO, BN, then you can imagine that the opportunities will be limited to female counterparts who are barred from those positions in the first place.