and Rian had to have his umpteenth subversion.
Buy Rey rejecting Kylo wasn’t a subversion at all. Having her join him would have been a subversion, since we expect the hero to reject the offer to join the villain, like Luke and basically every hero in every story ever.
But Rian = The Worst Thing That’s Ever Happened to Star Wars, so gotta make stuff up to be pissed at him for when there isn’t anything there I guess, huh?