1966 Plymouth Valiant Wheels/Tires

Is there any rhyme or reason why it was done that way?
I believe the theory was the wheel rotation would keep the nuts tight. Chrysler used them up to 1971, then all right hand. GM dropped the lefts much earlier.
You can change the studs to right hand & make lug nut selection simpler. Especially if you switch to mags.
SpeedyEd