I felt this move shat on Luke, in favour of setting up a new platform for new characters. Luke saved Vader and then hid away after some nephew problems. Didn’t seem true to the character.
According to a number of things I've read, initially Mark Hamill hated the script, but was eventually convinced and now fully embraces what Rian Johnson had Luke become. So if Luke's OK with it, I think we should be too. :)