until the 70s sometime ALL film was cut with a leica leader like that. They quit when they started selling all those point and shoot cameras with auto-load that didn't need a long leader and might not even work as well with one, since they usually needed both sides of the sprocket wheel engaged to drive the film properly.

By then LTM leicas were pretty scarce, relative to the zillions of other cameras out there, and weren't a factor in the eyes of film makers. The few still using them could fix the problem with a pair of scissors.