Daxtreme, the problem with Luke’s entire arc in the film is that he already learned the lessons of failure in the OT. The way TLJ plays out is as though Empire and Jedi never actually happened, and Luke never learned the lessons that he in fact did learn in the earlier movies, so he never actually teaches Rey anything in a believable way.
He tries to whack Ben “because dark side” (total BS)
He then wallows in self pity and she learns from that? She leaves Luke after she gets fed up with him and he with her. That’s not a lesson. Luke doesn’t even teach her the lesson of failure, she has to beat a confession of wrongdoing out of him with a stick and lightsaber.
1 “Lesson” is how the force exists beyond light and dark and pervades everything (we already know this, so does Rey from Maz in TFA.)
2nd “Lesson” is that neither side has a monopoly on the force, and the Jedi in their arrogance allowed the Sith to rise from their own ranks. (Luke repeats the same mistakes his own masters made with Anakin due to merely “sensing the darkness” in Ben. That is a betrayal of the character’s whole arc in the last trilogy.
3rd Lesson was cut from the film.
Rotoscoping a saber where Luke’s staff is would be done to re purpose those shots for a kind of Luke V the Knights of Ren shot in a force back, or maybe a Luke V Ben shot where Rey is seeing things from Ben’s perspective. You could put audio over this of “let the past die” and “this is not going to go the way you think!”
Mark Hamill had his own backstory for why Luke exiled himself, namely losing a child. I think if Luke was training Ben and his other students during a time of his own personal crisis,
(something beyond his control and just natural) this would make for a better rationale for Luke to fail them all, and also for Ben to turn. (a rationale was never given beyond “because Snoke, and Because dark side.”
Imagine if it could be implied that Luke suffered a loss and therefore loses faith, while Ben is committed to the Jedi code of no attachments, but being twisted by Snoke. (let the past die = be free of attachments, which is a Jedi ideal,) but Luke sees the rigid interpretation of that ideal as THE problem of the Jedi that needs to end.
The blame going to Luke for Ben’s turn falls flat because the Luke of the OT wouldn’t make those mistakes. “always in motion is the future.” What lesson did Luke learn after getting his hand chopped off if not “don’t jump to conclusions based on a force vision?”
It would be more intriguing if Luke was in fact the “great Luke Skywalker” of Legend, but a basic aspect of life (like losing a child) is what brings him down despite his being a full Jedi and having that discipline, and even despite being able to integrate a family life.
The way that TLJ presently frames things, Luke never learned from any of his experiences, and stayed a frightened boy who was mistakenly ascribed legendary status.