Easterhay said:

Kersh did say, though, that he would never have shown Vader's/Anakin's face in ROTJ. I think that would have been a mistake.

I remember reading that interview with Kersh where he talks about ROTJ. Kersh just had a whole different idea where the movies should go, and that is why he never would have shown Vader's face.

His argument was that the mystery of something is much more powerful then when you actually show it. He was essentially saying the Prequels should never be made for that reason too.

There was a mystery about Darth Vader, and once you unmask him in ROTJ, or once you show his backstory in the PT, everything is out there and you risk allienating fans who don't ever look at Darth Vader/Anakin Skywalker the same.

Now of course Lucas wanted to put a face on Vader to show he was human, and that is essentially the point of ROTJ, but I do see Kersh's broad view of the movies, that sometimes less is more.