Left side lugnut studs

Hi guys

Why would someone install left sided lugnut studs on one side of a rear end? Just figured out why I damaged my wheel with my impact gun trying to take off some rusty lugnuts. Any thoughts?
Mopar did that from the factory from i think 1962-1972? driver side came with Left hand thread it should have a L stamped on the stud. Why i dunno? i heard so the consumer wouldnt be able to take their tires off and have to take them in to get serviced