But here is where and why ROTJ is the oddball. Luke has faced Vader and lived. He starts out the story by rescuing Han. Jabba and his main henchmen and hangers on are all dead. Luke has mastered the powers and skills that Yoda taught. Luke is at the top of his game. He is the last Jedi (save Yoda on Dagobah). He turns himself in to Vader rather than risk his friends. He starts of determined not to fight. Why does he fight? The Emperor taps into his failings. The ones we’ve spent two movies dealing with. He incites Luke to draw and fight. That and Vader doing the same thing a little while later prove that Luke is not the poised Jedi Knight he is pretending to be. ROTJ shows that Luke is not perfect, but the overall impression is that he is now a full Jedi Knight. But he has a lot to learn yet. But now he has no teacher. The cracks showed on the Death Star. So when years later he establishes a Jedi school and half his students turn and kill the other half, Luke’s wave of success crumbles and his failings show for all to see. Just because they are nicely hidden in ROTJ does not mean they are not there. Many fans have speculated that he almost turned to the dark side - that he actually drew on the dark side to defeat his father. He has his father at his mercy and he hears the Emperor urge him to finish him and listens to something else that makes him stop and throw down his light saber (something he evidently did in a more permanent way after the fall of his school).
But to say that ROTJ clearly shows a changed Luke ignores all the flaws that the movie shows are clearly still there. The Luke of ROTJ is riding a wave of success and has matured, but those old tendencies to defeatism and recklessness are still there. Rian tapped into all the complexities of Luke from the OT when crafting the story for TLJ. If you gloss over the flaws that ROTJ shows are still there, or just ignore those parts of the movie, you get Luke the epic Hero. Luke the Legendary Jedi Knight. When you dig you find Luke the person and that person would do exactly what JJ and Rian have said he did. Even Mark Hamill has fallen for Luke the Hero. But once he got past the surface and realized what the story did, he agreed with it.
ROTJ is the aberration in Luke’s journey because it was his greatest success. His flaws were under control.
Well this is where it gets really interesting for me, because I actually think Luke’s actions in RoTJ are morally bankrupt. The essence is fine - Luke realises that he is a liability and turns himself in so that the mission can proceed. That stuff is great.
But the details ruin it for me. Luke says to Leia “if I don’t make it back, you’re the only hope for the Alliance”. This is arrogant nonsense. As I mentioned earlier, Luke is nothing but a liability. Furthermore his showdown with Vader/Palpatine has no bearing on the mission or the war.
Then he states that his mission is to try and turn Vader back to the ‘good side’. This is selfish in the extreme. Vader is a war criminal, a profoundly evil man. While it might be a nice idea for Luke personally, Luke’s primary focus should have been a) getting out of the way (which he stated) and b) taking down the Emperor even if it’s by way of making sure Palps is on the Death Star when it goes boom. That would be a noble mission and a very worthy one. Instead Luke’s spoken stance is “while you guys fight for the galaxy’s freedom I’m gonna go save my war-mongering dad”.
I will never understand the ethics of what goes down on the Death Star. Luke, a man who has killed countless enemy numbers and to great applause, suddenly decides that total pacifism is the key here - and only because he selfishly wants daddy to turn good. While people are fighting and dying all around him for the cause of freedom against a brutal dictatorship, Luke is hiding under a stairwell refusing to fight. After losing his temper and (rightfully IMO) beating Vader to a pulp, Luke throws his weapon aside and proudly declares his own enlightenment. Again, an actual war is being waged outside, and Luke is busy congratulating himself on his personal spiritual victory. He doesn’t challenge the Emperor. He doesn’t attempt to address the carnage being wrought by the Death Star or at least get Palpatine in a headlock and force him to recall his forces. No, he just stands there and boasts “I am Jedi”. Great. Meanwhile the actual galaxy is being saved by Chewbacca who has had the foresight to hijack a Scout Walker. Give that Wookiee a medal please!
So Luke gets fried and Vader, seeing his own flesh and blood in danger, kills the Emperor. Suddenly killing the bad guy becomes a viable path to enlightenment. Uh, okay. Vader and Luke hold hands and all is wonderful.
At best you could argue that Luke inadvertently prevented Palpatine’s possible escape from the Death Star. But that was just a lucky consequence of Vader’s sudden sense of paternity. Luke’s actions had no bearing on the war. For all the build-up, for all the ‘that boy is our last hope’, Luke was pointless (outside of recruiting the Ewoks). If anything the idea of training a new Jedi Order - ie a bunch of guys who aren’t allowed to fight and could turn irreversibly evil at the drop of a hat - is ludicrous. The idea of Luke even becoming a legend for his actions on Death Star II is laughable.
The only thing Luke has going for him at this point is his unwavering dedication to family over doctrine. Remove that and you’re not left with much.