Whether or not that’s true, it seems that Rian Johnson may not be the one to blame, as it appears Luke’s decision was made back in 2013, before even Star Wars: The Force Awakens was made.
One of the major criticisms that has been leveled at Star Wars: The Last Jedi, and its writer Rian Johnson specifically, is that it handled Luke Skywalker wrong somehow.
At least, that’s according to Christian Alzmann, who drew one of the earliest pieces of concept art of Luke for the new trilogy.
That Luke’s portrayal as a man who abandoned civilization to die alone was improper for the character.