The way they disrespected the past (spoilers)
My background on this movie, zero, I watched no trailer, zero promotional images, no posters, no behind the scenes, I knew only the title, I watched away and covered my ears when a trailer or image appeared, I am not a super fan but know the movies from the 80s - 90s.
I hated this movie, it was the sum of all the little things from the very beginning with the lightsaber tossing, the endless Marvel CU style comic relief, the new characters with zero background that feel hammered in to force a "hope" message for the future movies, the pointless filling with story arcs on casinos, the extremely stupid dead of the main bad guy, Yoda casting lightning storms (why didn't he appear in front of Snoke before and killed him with lightning or some other magic trick), etc.
But, I could have forgotten ALL of that if they would have respected Luke at least at the very end of the movie, if they would have pulled another "Yoda fight" scene ala Episode 2 next to final scene, something to show that Luke's power go beyond of a stupid force teleportation (cool but that was the last thing you will see of that iconic character and his years of training before going crazy), that character deserved better in a lot of ways.
I am all up open for the future, they can change all they want to get rid of the Lucas stories or the Skywalkers, but the way they threw everything away seems very hasty and uncalled for, at least give your characters a proper ending, even Han Solo had a better ending than Luke's (and that is saying a lot).