Ok, I know this opens a bad can of worms but I need to get this off of my chest. This is only my opinion and not a fact. If you disagree with me that's totally fine and I understand I am in the minority here.
Let me start by saying that I have only been a fan for two years. I haven't got into the EU at all. I had zero interest in seeing Luke as an infallible force God who can take down the first order. I would have been disappointed if he wasn't at all affected by Kylo 's betrayel yet I fundamentally disagree with everything Rian did with Luke in TLJ. And to clarify I have no problem with Luke failing, or having flaws, or making mistakes.
Let me start by addressing the elephant in the room, Luke attempting to murder his nephew and I won't attempt to downplay things here. People make the point that Luke saw a lot of darkness within Ben Solo so out of compassion for the Galaxy, his first instinct was to kill him in his sleep. This is a good point, but I think love tends to overcome fear. When you see a loved one going down a wrong path you do everything you can to save him as your first instinct. A parent wouldn't draw his gun and point it to his sleeping child if he finds out he is contemplating joining ISIS for the sake of the greater good. Obi-Wan wouldn't draw his light saber over a sleeping Anakin if he senses darkness within him. Anakin wouldn't draw his light saber over a sleeping Ahsoka if he senses darkness within her and Luke wouldn't draw his light saber on Leia if he senses the same amount of darkness in her.
Alot of people site Luke lashing out at Vader on the death star II as a parallel to this scene. They say that Luke lashed out to protect his sister the same way he lashed out to protect his loved ones from Ben. I disagree. Vader was a very real, established Sith Lord who had killed Luke's mentor, cut off his hand and tortured his best friend. Luke had hated Vader for a long time and even though this hatred dissappeared after the revelation in ESB, this doesn't completely remove the anger. Yet Luke chose compassion over Anger and believed that there was something worth saving in Vader so he went to confront him. Vader failed him and took him to the emperor where he expected to die. The Emperor proceeded to tell him that everyone he cares about are about to die and that the only way to save them is by becoming the very thing he stood against. Luke attacked to end all of this but Vader continued to fail him. He had to fight in order to keep his anger from consuming him and to remind himself of the good he feels in Vader. He ran away from the fight despite gaining the upper hand because he was under enormous pressure and didn't know what to do. It's only when Vader threatened to turn His sister did Luke's considerable self control break. Most people wouldn't show half the amount of self control Luke shows in that scene.
In the other scene, this is his nephew, the son of his sister and his best friend, who had done nothing yet and was sleeping. The idea of Luke losing control over sensing a lot of darkness in his nephew in my opinion goes against the established character and completely ignores everything Luke learned and became. Some people say that surely he saw more darkness in Ben than Vader and didn't see the good that was in Vader but Rian himself said that Kylo isn't as evil as Vader. Luke conveniently sees unspeakable darkness and fails to see the death star sized melodramatic conflict within his nephew despite sensing the conflict within Vader. And Kylo conveniently wakes up to see the Saber and misunderstand. A plot driven by a misunderstanding may work for a FRIEND'S episode not for an epic space opera especially one whose main theme is arguably that our choices determine who we are.
However the fact that Luke wouldn't contemplate murdering his nephew is only half the problem for me. The other half, the more important half imo, is that Rian portrays Luke as a faliure without telling us how he failed. Kylo Ren's fall to the Dark Side is the event that sent Luke into Exile and destroyed Han and Leia's relationship. It's arguably the central event of the sequels and yet up to this point we have no idea why did Kylo abandon a loving family for something vague and meaningless.
Luke is portrayed as someone who questions his judgement but it wasn't a lapse in judgment that we saw but rather a moment of pure instinct as Rian puts it.
People say the theme of the movie is faliure but we don't learn how Luke failed. Having a moment of weakness isn't faliure, Making a wrong decision is. If Luke is going to be portrayed as a faliure who questions his judjment then let him make a bad discisson that lead to his faliure. He also doesn't learn anything from his faliure that he didn't already know. As shown in ESB and Skywalker Strikes, Luke isn't a stranger to faliure or tragedy and he always emerged stronger and attempted to better himself, and he never ran away from his responsibilities or abandoned his loved ones.
Then you have Luke's attitude towards Ben. He resents his nephew and abandons him to the dark side despite Fighting tooth and nail to save a father he barely knew. He proclaims him to be irredeemable despite everything saying other wise. The idea of some girl teaching Luke to see the good in others make me want to vomit. Luke is factually wrong in every aspect until he died.
Don't get me wrong Luke would never walk away from Kylo's betrayal unscathed. He would feel anger at Ben for killing the students he no doubt became attached to. He is going to grieve and mourn. He is going to question himself and feel responsible even if it wasn't his fault. But he won't run away and abandon Han and Leia in their most desperate hours. He is going to try to figure out what went wrong and he would try to fix it. He is going to try to see what led his nephew down the dark path and see if he can save him, and if he realizes he can't, he is going to try to stop him because he won't be okay with more blood on his hands. He won't run like a coward because he was always tenacious, responsible, selfless and Loyal to those he cared about.
At the end he fought and suffered his entire life for nothing. Very meaningful considering he passes a lie not a legend. Any sane person who hears his story would lose hope instead of gain it.
I realize I can't change anyone's mind but I only wrote this to gather all of my thoughts in one place.
But in my opinion, Luke Skywalker deserved better.