Please understand.... We are not going to come to anything like a "correct" interpretation of Luke's characterization. Art is consumed subjectively...by definition. So I have no problem accepting your judgement that the traumatic events that befell Luke in the later stages of his life since ROTJ fundamentally altered his view of life in general, the Jedi in particular, or how he saw his place in all of it.
What I have a hard time with is that people who hold the view of Luke I just tried to describe above have SUCH a hard time with, and almost NO tolerance of MY perspective and that of others that feel that despite all that he has faced, extinguishing the fire of the "New Hope" who was always driven by the instinctual need to protect his friends and defend all that he loves didn't feel organic with his story.
Now, movie making is a process, and the writer/director, has wide abilities to take the lives of his characters in any direction he chooses. Fine. But we're not required to like it. And it doesn't mean that "I didn't GET it", what it means is I GOT it just fine, it just didn't work with my personal and subjective understanding of the character of Luke Skywalker.
And if I have to "get over" the idea that many people loved the depiction, then others will have to "get over" the idea that I felt differently. All of which is insane, because all we are, are people with a different opinion of a movie. Who cares! Love it/Hate it, we're all on board for Episode IX!