We've talked about this some before, but I think it's a....hmm....middling middle film. The problem with a middle chapter is that it depends entirely on what comes before and what comes after. I think that had RJ done the entire series, TLJ would've been indisputably amazing. But following on the heels of JJ's TFA and then being follwed by ROS, the entire thing ends up diminished because the parts just don't work together. I mean, they work....enough....but tonally they're so wildly different that it ends up being really jarring.
I mean, that happens to plenty of people who are naive and wildly idealistic in their youth to cynical and embittered in middle age and later life. That's....kinda just life, ya know? I'd also argue that JJ set up a lot of this, albeit perhaps inadvertently.
Like, ask yourself for a second "Why was Luke all alone on that planet for so many years, in spite of all the stuff going on in the galaxy?" What would the reasons be? Why would Luke abandon the Republic and his friends and the Jedi?
Simply putting Luke on the planet alone already introduces the whole "Luke is tarnished" aspect of the films. The Luke hero of the OT
wouldn't have gone in the first place. The guy that many people were expecting to see would have stuck around, would have fought to save Ben, would have tried to redeem him earlier, etc., etc., etc. Instead, TFA opens with "LUKE SKYWALKER IS MISSING!!"
Now, my guess is that JJ didn't really have a clear idea
why Luke was missing, or at least his ideas were sort of hazy and not all that defined. I suspect JJ removed Luke from the picture for mechanical reasons, namely "There's no way to include this incredibly powerful Jedi master in the entire story, and also have the new generation be effective heroes. So, we have to sideline him. Ok, send him off to a random planet for the first film, and have Rey find him at the end and...uh....we'll.....figure it out later. Now, say the lines faster! More intense!"
But when you start unpacking what possible things would have made Luke leave AND stay gone at this time of need, the list of reasons starts getting pretty short. Having such an utter personal failure as his moment of contemplating killing Ben? AND the associated devastation that follows in the wake of it? (Snoke gets a new dark side recruit, Han and Leia split up, the Jedi are destroyed again, all because Luke had this moment of weakness.) All of that would make good sense as to why he'd hide away: he's deeply ashamed and believes that he himself is more of a problem than a hero. All of that makes perfect sense internally. All of it explains why Luke is gone in TFA.
It would arguably make even
less sense to have Luke be off meditating while the galaxy is on fire, and refusing to come back, only to have Rey show up and for him to say "Ah. Once again, I must return to the fray. Come with me, my young Padawan, and I shall teach you to kick Sith ass all the way back to Korriban." That might be satisfying for fans of Luke, simply because it's fun to watch him kick ass and teach an apprentice, but it wouldn't jive narratively. It's EXACTLY the kind of thing that JJ would have done if he'd been in charge of the 2nd film, though, because it's all about what feels nice in the moment if you don't really interrogate it any further, but -- again, just like JJ's films -- if you stop and think about it for, like, 3 seconds you start saying "Heeeeeeyyyyy.....what the hell?!"
So, long story short, blame JJ for the setup of removing Luke from the film, without bothering to think of
why Luke would be gone in the first place.
I think a lot of this got overblown, and in many cases by the people who really did like the film. You can not like his film and not be sexist, but a LOT of the dudes who were really vocal online were absolutely sexist, and many said some seriously sexist and racist things towards Kelly Marie Tran. So, those people get a harsh response, and then fans of the film jump on and shout them down, and THEN someone else comes along and says "I didn't like it because it didn't jive with my idea of who Luke is" and the fans jump on THEM as well. But that's just internet fandom and the dumpster fire that is Twitter.
But there absolutely was sexism and racism involved in a bunch of the criticism of TLJ. That wasn't the entirety of it, but it was there.