If you want to see my spoiler-free review of Star Wars: The Last Jedi, look here. Otherwise, expect plenty of spoilers.
If you look at some of the youtube reaction, it is clear that a great many people hate this movie. These are the die-hard Star Wars fans who are more than likely older and feel an attachment to the existing Star Wars mythology. The reason why all these people hate the movie is pretty much the same: The movie throws away the old mythology and replaces it with a slightly different version. In fact, that is the theme of the film, because in a least of a couple of places the movie says, "Let the past die. Kill it if you have to." We can see this in the first Luke Skywalker scene where he symbolically and humorously discards the past like it has no meaning.
Whereas the movie should be the continuation of the hero's journey, Luke's journey, what we see instead is a disenchanted Luke who has abandoned his friends, their cause, the Force, and the Jedi Order. No wonder some people hate this movie!
I have seen multiple people claim that Star Wars: The Last Jedi kills Star Wars. I disagree for the reasons I give below.
These same people who have problems with the movie have also noticed that the new trilogy is an outlet for Social Justice Warriors. All the bad guys are inept white males. The leaders of the rebellion are all women, and the lead male characters make mistakes, get into trouble and have to be corrected by the females. In fact, when the producers cast The Force Awakens they stated they were making an effort to not cast white males, as if Star Wars needs some form of Affirmative Action. For example, Oscar Isaac who plays Poe Dameron is Hispanic. We can see the social justice theme in several places in the movie since the resistance is described as "the voice of the downtrodden" and the planet of Canto Bight is described as a playground for the rich who just happen to be mostly white and war profiteers. Meanwhile on Canto Bight, the stables for the Fathier, which are like space horses, are maintained by child laborers, apparently slaves, who are clearly oppressed but secretly yearn to side with the rebellion.
Whereas the old movies had a clear moral distinction between an evil empire and freedom-loving rebels, the new movies blur those distinctions a bit. It has become more of a struggle for the oppressed against the rich and powerful. Snoke, who is supposed to be the ultimate bad guy, was described in the prerelease publicity as rich and powerful and flashy in the way that he liked to dress adorning himself with jewelry. He was also supposed to have a connection to the playground of the rich world of Canto Bight. In Star Wars: Rogue One, Saw Gerrera is a terrorist with parallels to Che Guevara. So who exactly are the Rebels? Political leftists? What cause are they really fighting for?
There is a lack of continuity with the old films in that being powerful with the Force required some sort of heritage, such the Skywalker lineage. Many people thought that Rey would be Luke's daughter or the granddaughter of Obi-Wan Kenobi or somehow related to Leia or Palpatine. Instead, we are told that she is literally nobody; her parents were junk dealers who sold her into slavery for a pittance. But here emerges a new theme, which is that anyone can become powerful with the Force, regardless of heritage or lack of training. In fact, the new trilogy seems to think that training is not important. Luke doesn't train Rey, except to tell her why he thinks the Jedi cause must end. So despite her lack of training, Rey is able to leave Luke and go off and do powerful things.
There are things in the movie that don't seem logically consistent to me. The previous films established rules on how the Force works, or how the space ships worked and how their propulsion worked. This film establishes new rules. For example, if you can destroy a battlecruiser with a kamikaze run then why haven't we seen that before? And why does a human have to do it when we know that droids can fly ships? Fuel has never been an issue before, but here it becomes a major plot point. And why can't the First Order ships catch up to the rebellion ships at sub-light speeds, when their starships are capable of going faster than light?
People expected this movie to provide them with more information, like filling in the back story on many of the characters, but the movie is stingy with its information and only gives us enough to allow us to follow along.
Character development suffers a little because the movie has too many characters, but it is good enough.
The good news is that despite the film having a different vision, it is still a vision worth following. Every time the movie would deviate from its Star Wars legacy in any way, it would quickly go back to its Star Wars roots, which is enough to keep a fan like me happy. The movie is exceptionally entertaining, mainly because Lucasfilm and Disney tried to cram too much stuff into it. They throw in a great deal of humor, almost too much, but it works by making the movie that much more fun. Although Star Wars The Last Jedi is not a perfect Star Wars movie, it is nearly perfect as a movie because it thoroughly entertains the audience.
I'm not going to give it a final rating until I can see it again. My gut feeling is A-, but it feels like an improvement over The Force Awakens.