Pre 1971 in the Australian area there was no obvious history of landing light use at height. The first time I saw it used was in DC3s in Papua New Guinea during famine relief flights in 1971/1972. VMC (well, almost) at 12000ft it was usefull to see opposite direction lights. With very high terrain, weather and poor performance, there was not much chance for level choices to give vertical separation. After that landing light use spread to Australia. Maybe we spread it to the rest of world?
It was a good idea then and still is.