When Star Wars: The Last Jedi came out, fans were infuriated with the way Luke Skywalker was treated, as many felt that he wouldn't give up his previous optimism after one (fairly fatal) mistake. Some fans have also felt that director Rian Johnson went against all of the things that J.J. Abrams planted during The Force Awakens, including Luke Skywalker's character arc.
It turns out that those fans might be wrong, as a piece of concept art from 2013 revealed one of Luke Skywalker's earlier designs, with Lucasfilm design supervisor Christian Alzmann saying that the Jedi would "hiding from the world in a cave." That is huge news, as this was his main storyline during The Last Jedi; wanting to die alone after his actions caused the deaths of many young Jedi (or younglings, depending on who you ask), which was understandable.
Now, just because this was planned from the very start doesn't mean that Mark Hamill was all the way okay with it. In fact, Hamill was actually against how Luke was portrayed but eventually let it be since this is many years after he saved the galaxy from the Empire. This move might not be popular with some sections of the Star Wars fandom and that's okay.
To this day, fans are still split 50/50 over what happened in Rian Johnson's Star Wars: The Last Jedi. Some of the less-hardcore fans felt that the film has some of the best and worst moments in a Star Wars movie, which is a bit hard to argue with. As someone who likes The Last Jedi, I can agree that Finn's little casino adventure was kind of dumb.
Star Wars: Episode IX comes out next December.