I think Mark Hamill doesn't quite understand the Luke Skywalker character.
Really great analysis, but that seems to also apply to Star Wars fans as a whole.
What's funny to me is my idea of Luke as a fringe fan of Star Wars. I've seen every movie, and I appreciate them all. But they're not movies I've seen a ton of. I've seen A New Hope a couple dozen times, but I'm not sure I've seen Empire or Jedi more than a couple times each all the way through (I've seen pieces of them a lot since they're always on TV). In a recent discussion about the quality of the prequels, I realized that I think I've only seen episodes II and III once each (again, aside from scenes here and there on TV).
But, for some reason, Luke holds a place in my heart. And as Episode VIII approached, I started to worry that Luke could die. Or, possibly even worse, go to the dark side. I felt that, in some way, my heart would break a little for him to not be alive. After all, he'd been alive and young my whole life.
The movie actually handles Luke, for the most part, in a way where I was okay with him going. After all, we know Luke will live on in the Force so he's not really gone. And even as someone who's a fan of Luke, I wasn't really bothered by the Luke stuff in the moment. I was surprised, but I wasn't offended.
I agree with everything you said. Luke is, on paper, a cold-blooded killer. I watched "Kiss Kiss, Bang Bang" the other night, and Robert Downey Jr. gives a great performance when his character shoots and kills a bad guy in the middle of the movie. He breaks down at the idea of shooting someone....even as a career criminal who killed a truly bad guy in self defense. As you said, Luke killed millions of innocent people but doesn't really seem bothered by it.
And yet....killing a child in his sleep? At least Anakin did it to the younglings when they were awake and could, at least theoretically, defend themselves.
The only thing I can really think is that they wanted Kylo to have this tragic backstory. And it really does make him a truly interesting character. Kylo is this kid who romanticizes his grandfather (who had his own tragic backstory) and feels this pull to the Dark Side. He has this mother who cares so much about her Rebellion and a father who's not really built for fatherhood. Then his parents sent him away to live with his cooky uncle, while this other dude is pouring propaganda in his ear from across the galaxy.
Then, one night as he's as conflicted as ever, his uncle tries to kill him. Whether or not Luke meant to do it or not, that's Kylo's backstory. He truly believes his uncle tried to kill him. And then he starts to wonder....wait, did my parents send me to die? Is all the love I had as a child a lie? Is the only one who has truly cared about me....Snoke?
It happens all the time. Kid gets betrayed by his/her family and falls into the arms of an abusive relationship.
The problem with the Last Jedi is that it doesn't really excuse any of it. Even with all the talking from Kylo and Luke, there's still not enough context to understand what really happened. What did Kylo really do that scared Luke so much? What did he do where Luke would even consider that Kylo couldn't be saved?
You say that Luke was working off instinct, but that's not really what Luke says. If he'd explained it that way, I think there's a chance they could've sold it. When I watched it, it seemed like Luke was saying that he *did* want to kill him, but it was just for a moment. Because he definitely walks in, thinks about it, and then ignites the saber. It didn't seem, at least to me, that he got caught up in the moment.
So to me, and to a lot of people in the audience....they turned Luke into a guy who'd consider murdering kids. And, yes, I agree that he's probably killed kids in the past (you'd gotta think that some families were on the Death Star). But this was so much different that that that, I think, it really bothers people. Thus the hate.
And so I wondered, was there a way to give Kylo this cool backstory without harming Luke's legacy? Some ideas:
1. I like the idea that he's working off instinct. I also love the idea that Luke, flat out disagrees with the teachings of the Jedi. So what if you combined those two things? Luke goes to the Jedi Temple and learns an old Jedi technique for defeating evil - Force Meditation (name can be workshopped). As a Jedi Master, Luke can meditate and enter a sort of trance where he becomes one with the light side of the Force and can seek out true evil.
Luke enters one of these trances in an attempt to find Snoke. And in a sleepwalking state, he finds a strong Dark Side presence, and the Force Meditation draws him to it. And draws him to destroy it. Maybe it's Ben himself or maybe it's Snoke's Force projection.....but either way, Luke (still "sleepwalking") ignites his lightsaber. Ben wakes up....and so does Luke.
So Luke isn't doing it...this flawed Jedi artifact did it. The Jedi aren't interested in saving people - they're interested in killing bad people. If the Jedi had been around to fight Vader and Palpatine in A New Hope, they'd have killed Vader and then lost to Palpatine. It took seeing the good in Vader to save the galaxy, and that's why the Jedi are flawed.
2. Do the twin brothers. I know in the (abandoned) expanded universe, the Solos had twins. So maybe you bring that back. Ben and Lando Solo are twins that are sent to train with Luke. Ben is a quiet boy with a strong love for his family. Lando is a wild and rebellious son with an obsession with his grandfather Anakin. At the Jedi Temple, Lando keeps asking about the Dark Side. He starts experimenting. He builds a....red lightsaber. Ben tries to talk to him, but he loves his brother. He wants to save him from these dark thoughts. Lando is drawn away from Ben to a new father figure - Snoke. And through Lando, Snoke starts telling Ben that their family abandoned them. Han and Leia don't love them. And, one day, Luke will try and kill them.
At training, there's a tragic accident. Lando is sparring with another student and accidentally maims/kills him. Ben is horrified - Lando doesn't seem bothered by it. Luke keeps an eye on him....and, yet, it happens again. So Luke, in the middle of the night, goes to take Lando away from the Academy. Lando defends himself with his lightsaber. Ben wakes up, Luke loses his concentration, and Luke slices through Lando.
Luke has no time to explain. Ben simply sees Luke kill his brother, and Snoke's prophecy is coming true.
Luke does kill a Solo twin - but it was one who was definitely a Dark Side user. But it still drives him to exile, and it still drives Ben to become Kylo.
3. Just make it the Dark Side. What if Snoke was influencing them both? What if Luke starts seeing all the students turning evil....not just Ben? Meanwhile, Ben is getting the same sort of influence? Luke doesn't sense it, but Snoke starts feeding the lies to Luke. "Your nephew is evil." "Your uncle will try and kill you."
And Luke falls for it. He lets his hate and his fear and his jealousy turn him to the Dark Side....and he tries to kill his nephew.
Mark Hamill wanted this as far back as Episode VI. He thought it was where the saga was going and pitched it to George Lucas - so it would've been interesting to see that come true on the screen. It wouldn't be a full Dark Luke - just enough Dark Luke to try and kill Ben.
Luke snaps out of it, but it's too late. So he does go into isolation and close himself off from the Force - he can't trust it again, and it keeps him safe from Snoke's influence.
I think if you do something like that, you protect Hamill's vision of Luke. Which, it seems, is a lot of Star Wars' fans visions of Luke.