That since they marginalized both Rose and Leia in ROS, it would have strengthened Rose's character if she had died saving Finn in TLJ. Which is hindsight, of course. And since Carrie Fisher died before TLJ came out, it would have made sense for Leia to die when Kylo Ren blew up her ship rather than try to force her into ROS where she died anyway. That would have made Ren's character redemption even more powerful, having killed both his parents.
Basically, while I had some problems with TLJ, what Abrams tried to do when he took over ROS made those problems stand out even more. I would have liked to see Rian Johnson's version of the final film. I think that he would have used Rose more and had a more fitting ending for Leia.