To explain Luke’s transition would not be for the sake of appeasing fans, it would be for keeping the narrative sound despite a 30 year gap in the story. Also,

Broom Kid said:
His failures didn’t ruin him. They eventually made him even greater. That’s inspiring to me. Even good people fall down. That doesn’t make them bad people. It just means they need to work harder at remembering who they can be, and moving back towards that light.

This is verbatim the themes shared by Luke and Anakin in the OT. Such drastic departure and character change only to accomplish the same exact moral in a less satisfying way (in my opinion).