I just watched the video that jjss49 posted, and it seems pretty clear to me from the explanation the guy gives how this works, and why it should be better. The optical conversion prevents electrical noise from crossing where an electrical conductor would let noise pass.
There are probably other ways to get electrical noise out, like filters using capacitors resistors inductors but if you just watch the video and listen to what is said the explanation is right there.
What the hell is the complaining about?