I have to share this and put in my two cents. Why? Because of how completely and utterly WRONG this all is theory-wise. First of all, ROTJ was a great ending, and what most people get wrong about Luke was how he WAS the chosen one and DID bring balance to the force. You can’t have balance with the dark side in power (Nevermind that the whole ‘prophecy’ thing was added prequel stuff anyway). Okay, so on to your complete misinterpretation (to support your own theory) about the ending of ROTJ. Yes, in fact, what what happening when Luke looked at his own hand and realized what he was doing (oh no!) was in fact CORRECT. He did see that he was giving into his anger, fear and hate just as the Emperor foresaw and wanted. But right then was when it all turned. Not Yoda, not Obi Wan, not ANYONE saw what Luke’s true power was. The power his father never had. The power to RESIST. The emperor DID fail. And Luke WAS right about his father all along. There was still good in him. Yoda didn’t see it. Obi Wan didn’t see it. The Emperor surely didn’t see it. They felt the only way to succeed was for Luke to destroy Vader. They were wrong. Very wrong. “Then the Emperor has already won.” Obi Wan really did believe that, not only because of how hurt he was by how Anakin betrayed his friendship, but how blind of a follower he was of Yoda. If Yoda believed it, he believed it. But they again were wrong. But as you see at the end of ROTJ, they’re very happy they were wrong.