I recall reading (around fifty years ago) that this was an artifact of the Mopar stock racing legacy -- for quick pit stops, they used "spinner" wheels, same five holes we're used to, but for alignment only; held on by a single "knock-off" nut with three big fins on it (that the pit crew would smack with a rubber hammer to loosen and tighten). They quickly found that the wheelspin on a hard start (is there any other kind in racing?) would loosen those knockoff nuts, so they started making them left hand thread -- and then trickled that down to their street cars. They changed to standard thread around 1970, as I recall -- my parents had a '73 Duster (that my brother learned to street race in) that had standard thread on the lugs all around.
How the heck do you design a wheel so it needs left hand nuts on one side? I'm sitting here now trying to picture what sort of wheel/nut/stud interface could make right and left side
wheels not interchange...