While I do wish that Leia was the one to do the hyperspace trick, I also think it was important that her and Luke were on screen together one last time. I believe that Rian felt the same way, but kinda wrote himself into a corner; the way he set up the rest of the plot, the only way for Luke and Leia to meet again would require that Leia makes it to Crait.
EDIT: And I don’t doubt for a second that there would be bitching if they didn’t appear on screen together.