I still don’t understand why redeeming Kylo would have made it his story as much as Rey’s.
I’m not saying that. I’m saying his path to redemption needed to serve her story, ultimately, because the sequel trilogy IS REY’S STORY first and foremost. It’s not his. That’s not a logical leap. It’s not his story, it’s not structured as such, and it doesn’t play that way. It’s her story, and his role as villain is in service to that story. If you’re going to make him a good guy, it needs to happen in a way that resolves her arc just as much (preferably moreso) than his. Otherwise you’re just dividing focus and introducing confusion. This was also a big problem with the prequels, there wasn’t any unified focus to the storytelling.
The redemption of Kylo Ren is poorly done in TROS for a number of reasons, but one of the biggest is that it doesn’t really serve her story or close any of her arcs. His redemption isn’t a key want of hers as she heads into the finale, so when it happens, it’s not as meaningful as it should have been. Not only is his redemption not done very well, it’s not thematically clear who its for. If it’s for HIM, then it’s out of place because it’s not his story. If it’s for Leia, it’s really out of place because the only way that has any impact is through the audience carrying ALL of the water for Abrams via metatextual familiarity with the series. If it’s for Rey, then it needs to be the last piece that slots into her arc that reallizes it’s successful completion - but the movie tells us THAT happens on Tatooine, when she buries the sabers and takes a last name.
So it’s a redemption that doesn’t have a clearly stated purpose, doesn’t serve a primary thematic need, and isn’t done very well on top of all of that. I’m not saying it couldn’t have happened. I’m saying the way it did happen was very unsatisfactory on a number of levels, and the idea that other possibilities were tossed out before even being explored simply because “that’s not very star wars” was probably a mistake.