They definitely listened to a lot of the fan's concerns from Last Jedi. It seemed like they cut out the bullshit politics. They severely dialed back Rose's character, to the point she was almost not even in the movie which I thought was surprising. They killed that whole romantic angle she had with Finn. They poked fun at the "Holdo Maneuver" which I thought was beautiful. They basically retconned Johnson's angle with Rey's parents, going from "her parents were nobodies" to "Oh, she's a Palpatine!" Just a bunch of slaps in the face to Johnson.
One of the biggest negatives I've seen people come forward with is Palpatine in general. By bringing him back, people are saying that it basically cheapened Anakin's redemption arc in Return of the Jedi and it was just another fan service/callback. I did some thinking about this, and I concluded that Palpatine was a necessary evil in Rise of Skywalker (pun intended). When Johnson prematurely killed off Snoke it left a power vacuum in the antagonist roles. Who was left? General Hux (Who we find out later is a spy of sorts), and Kylo. Ben Solo was always going to get his redemption angle, they tease it in the very first film. If Kylo turns back to the light, who is there to drive the plot and push the protagonist Rey to the climax? No one, since Snoke is dead. What options are there then? Either you don't turn Kylo, or you introduce an entirely new antagonist and must build him up over the entire movie. The later is a pretty difficult task in the grand scheme of a trilogy though. You don't introduce Sauron in the final book of the Lord of the Rings, after all. So, what does that mean? Abrams' hand was forced, he had to bring back an established bad guy to fill the role. Palpatine was the most logical choice in this case. He had immense power in the dark side, there were references to the Dark Plageus story and his ability to cheat death. It may have been a bit unfortunate they had to bring him back, but given the damage Johnson did it became a bit of a necessity to tell a stronger story.
