Although Luke’s characterization in the film is almost certainly inconsistent with his characterization in Return of the Jedi, this is forgivable because of the vast time difference between the two films. Luke’s astral projection across the galaxy was a creative idea which aptly illustrated his mastery of the Force. His vision of the binary sunset before his death was beautiful.
Leia’s flight through the vacuum of space was almost unintentionally comical, but I could forgive this were it the only major flaw in the film. I will not criticize the humor because other Star Wars films have struggled with the appropriate level of comic relief.
By far the worst character in the film is Poe Dameron. The writers should have killed him off in the crash landing on Jakku in The Force Awakens. His reappearance in the film is utterly illogical. In earlier drafts of the script, Poe died in the crash landing on Jakku because his purpose to the story was fulfilled. In later drafts, J. J. Abrams wrote Poe back into the story despite implying he died on Jakku. Thus, despite his insistence on returning to Jakku to retrieve BB-8, he inexplicably leaves Jakku without it. In The Last Jedi, Poe Dameron is a thousand times worse. He consistently disregards the chain of command and lacks respect for authority. He disobeys Leia and in the process needlessly causes innumerable resistance fighters to die but is only demoted, essentially a slap on the wrist. Later, he even plans a mutiny. Yet Leia and Holdo speak fondly of him. In real life, after Poe’s first offense he would have been dishonorably discharged. After his attempted mutiny, he would have been executed for treason.
I hated Poe in The Last Jedi even more than Anakin in Attack of the Clones. While I could not empathize with Anakin, I could at least pity him because he was born a slave, was separated from his mother at a young age, and saw dreams of his mother in agony. In contrast, I was longing for Poe to die throughout the entire film.
Rey is an intriguing character, but her story would be so much more compelling if she faced failure. In the Empire Strikes Back, Luke was unable to lift his X-wing from the swamp. When Yoda lifted it for him, Luke was able to learn from failure. Vader bested Luke in combat and cut off his hand. In contrast, Rey bested Luke in combat. After two films in the trilogy, Rey never suffered a serious failure. The ghost of Yoda declared the moral of the story is learning from failure, yet the protagonist never wrestled with failure herself.
Finn should have died sacrificing himself to save the Resistance, a heroic act which would have been a perfect end for his character arc. In The Force Awakens, his goal was first to run away and save his own skin and then to protect Rey. Dying to destroy the canon and save the Resistance would have been a perfect end for him. Instead Rose stopped him from sacrificing himself. Her remark that they will win not by fighting what they hate but by saving what they love was a ludicrous cliché. Not all hatred is evil. All wars require sacrifice to vanquish the enemy.
Whereas Disney was unwilling to kill off any of the new heroes, it is willing to kill off one of the most intriguing villains in the saga. Snoke was not a Sith yet was more powerful than any dark side force user. He resurrected the First Order from the ashes of the Empire, and he seduced Kylo Ren to the dark side. The Force Awakens and The Last Jedi hint at a compelling backstory for Snoke but never deliver.
The revelation Rey’s parents were nobodies was neither shocking nor disappointing. It was practically expected for her to be a Skywalker, and it is unsurprising Disney would subvert audience expectations. At least the script provides a backstory for Rey, unlike for Snoke.
Rey’s vision in the netherworld of Ahch-tu was disappointing, especially when compared to Luke’s vision of Vader in the cave on Dagobah. Her vision of an infinite number of Reys revealed nothing unique regarding her character.
Lastly, it is difficult for me to regard Kylo Ren as a serious villain. He is undoubtedly evil, but he is not as formidable as Vader or Sidious.
Empire Strikes Back
Revenge of the Sith
A New Hope
Attack of the Clones
Return of the Jedi
The Force Awakens
The Last Jedi
The Phantom Menace
*Note: When ranking the original trilogy, I am evaluating the special editions.