He didn't save the teenage brat with the creepy look on his face. Imagine trying to go back and tell your 18 year old self everything you know at an older age. What do you think your 18 year old self would tell you? Probably to kick rocks and buzz off. The insufferable Anakin of the prequels was never redeemed.
Luke "saved" the old guy in the black suit. Old Anakin was the last good Anakin.
The only reason for that change was to shove prequel imagery deep down into your eye sockets.