I wouldn't be so sure.

Methinks it was the Germans with BMW, Zundapp and DKW.

Originally, Eurobikes had the gear lever on the right (1st up, top down) and the brake on the left.

Americans were true to their "twsit throttle, foot clutch and hand operated gear lever" ma(so)chismo.

Enter WW2 and sidecars equipped with machineguns etc. They were "LHD" i.e. driver on the left, sidecar on the right.

You needed the rear brake to operate both wheels, so it was moved to the right.

So the gear lever was moved to the left, by somersaulting the linkages within th egearbox. Literally!

As the Germans lost the war, their industrial kit was looted and shipped worldwide, and the "West" finally learned how to manufacture decent machinery.

Mind you, not that they learned much...

Shaft driven flat twins are THE bikes to ride around the world...
Chain driven V-twins are the bikes to show off on a Saturday afternoon...


... so they say ...