I'm not one for mandates, but I do wish manufacturers would be required to adopt standard controls. My four bikes have different control locations for the turn signals, horn, high beam, starter, kill switch, etc. It's not atypical to jump from one bike to another and have to relearn where the horn button is or how to signal or cancel a turn. It becomes natural once you have an hour on the bike, but they're all different and I've many times had to think too much when it should be intuitive (for safety's sake).
Certainly, it wasn't too long ago that some bikes had their gearshift on the right and their rear brake pedal on the left. And many bikes had shift patterns that were different from what is commonly accepted today.