I voted 5 but I wish I would go back and give it a 3 or 4. Anyone that saw me 'sperg out any of the previous SW threads knows that I'm a huge fan and only wanted good things for this installment.
There was a definite lack of a cohesive vision between the two writers; I believe JJ would have done a much better job.
The humor is inappropriate at most times because it didn't work with the tone of the film, or the scene.
The most egregious flaw to me was the cruiser jumping into Snoke's capital ship doing so much damage because that's not how FTL works in Star Wars. Now, this isn't an inherent problem in a sci-fi/fantasy world, but the issue is continuity. If a single ship can jump into another doing that much damage, there would be no capital ships - literally every capital ship would just have a small star fighter Kamikaze it. The Deathstar would be idiotic because a single cruiser could jump into the center igniting the core.
The Force Awakens left a ton of loose strands that I found really enchanting. It sparked a lot of conversation between fans and really just gave the universe back a sense of wonder that it had sort of lost - the Last Jedi did nothing with those loose ends other than quash that wonder.
While I love Poe as a character, the writing is atrocious. He and Holdo have this massive conflict on board the ship resulting in mutiny, but it is literally only because they do not communicate. Having two characters on the same side, in the same proximity not communicate isn't effective drama, it's just poor writing. Once Poe found out Holdo's plan, he literally agreed with it and would have helped.
Porgs. Fuck. At least Ewoks did something in the story, Porgs and crystal foxes are just to sell plushies and fill out whatever future Disneyland BS they have in mind.
Luke. I love Mark Hamill and his enthusiasm for the universe. When he said that he completely disagreed with the direction of the character in this film during an interview, well, it is easy to see why. The Force Awakens was literally an adventure to find Luke, then they find him, and the Last Jedi is still 80% 'finding Luke' in the heroic sense of him rising to the occasion.
Why make Luke this fallen hero? He was already tested in the Empire Strikes Back and Return of the Jedi. He didn't need 'to rise', he was already supposed to be a paragon.
On the good side, I still like Finn, even though the character he had to interact with the most, Rose, completely fell flat for me. Kylo was awesome - the actor and character just really grew on me. Rey is great. She has all the qualities of a young Mark Hamill - starry eyed, eager to please, but utterly defiant in the face of total evil. As a character / actress she hits the mark for me on all counts.