I've spoken about this several times in the past year. But this is my first time on these forums. As much as I understand your whole point about Luke's personality, I personally didn't agree with his depiction in Last Jedi. Not because it's the "popular" opinion. I felt like this on my first viewing before going on the internet to see the swarms of others hating on the movie. Now, at this point, my hatred towards the film has dissipated and I don't want to delve into a rabbit hole as I did when I initially walked out of the theater. So, I'll try to explain why I don't think his depiction was accurate.
First, I agree that Luke was known for acting impulsively, relying on his feelings rather than intuition. So, it makes perfect sense to me that he ignited his saber before Ben Solo in the hut. What didn't make sense to me though was Luke entering the hut in the first place. From my understanding, he sensed that Ben had a dark presence emanating from him. Now, I know Luke has shown traits of curiosity before such as him entering the cave on Dagobah. But, I truly don't think he would repeat this act if he'd known the source of the darkness was Ben. In fact, I can't believe this would the first time for Luke to sense this darkness in his nephew.
I think the Luke that redeemed his father would've arranged a session to speak with his nephew rather than creepily sneak into his private quarters and probe his mind. Luke knows first hand what it is like to struggle with the dark side. He is not like the Jedi before the Imperial era; the same Jedi who suppressed feelings of the dark side and refused to accept an individual that had conflicted feelings. Luke, and I would even say Qui-Gon Jinn, were more human than most Jedi. And by "human", I mean they were more understanding and realized that some people were imperfect.
My point being, I would've thought Luke would be a very compassionate and understanding counselor. I imagined him to be very down-to-earth, relatable, and more compassionate than any Jedi before him. Because that's who he was. And, I thought his character arc was always perfect in the originals because it juxtaposed with Anakin's wonderfully. It was love that created Vader, and yet it was love that redeemed him. Proving the Jedi of old wrong in their thought that love and compassion was always dangerous.
So when I saw TLJ, I was honestly baffled with the direction they took his character. In fact, I wasn't even expecting him to be such a main focus. I thought he was going to serve as the mentor figure to a vengeful Rey, who needed to understand the possibility of redemption in Ben Solo. But instead, it was the other way around. It was Rey who schooled Luke that there was still good in Ben. In turn, making Luke almost the central character with a fully realized arc in the movie. Yet, we'd already seen his entire arc in three movies.
At the end of the day, I don't care too much about it anymore cause I now express apathy towards the sequel trilogy. But to anyone who loves it, more power to you. I'm not here to dissuade from liking anything.
I just can't go against a legendary actor who played the role multiple times and voiced his disagreement to a director that was stepping foot into this universe for the first time in his life. How Rian Johnson got the keys to write and direct Star Wars will always be a mystery to me.