I concede the point, Brendon. My cameras focus backwards and the lenses come off backwards too.
I am thinking that there may be a historical significance to how it has shaken out. You mentioned how that Leica does those things, but not how Contax did them. Those were the two "biggies" back when the 35mm turf was being defined.
Canon took its design cues from Leica. The first Canons (~1936) were essentially affordable copies of a Leica rangefinder. Contax had a bayonet mount before Leica (1930s), but when Leica made their bayonet mount (~1953), they made it go in the opposite direction from Contax.
Nikon's first rangefinder got its design cues more so from Contax, and its lenses from Zeiss Contax. Those worked as Nikon's lenses do today. Dismounting clockwise, infinity focusing counterclockwise. Ricoh's rangefinders copied Contax too, focusing to infinity counterclockwise.
Nikon did copy Leica's rubberized silk curtain shutter. It was simpler to manufacture than Contax's vertically moving slatted shutter.
Contax is gone, but its focusing and mounting manners live on in Nikon.
Cameras come and go but the Leica remains; its lens operation mannerisms having become the norm.
This kind of reminds me of the Betamax vs VHS wars of a generation ago. Sony's Betamax was regarded by many as better, but VHS won the market. So, VHS became the standard for home videotaping.