I don't like that guy; is it just me?

You know, I forgot something else that was ridiculous from The Last Jedi: Leia being blown into space by her son and then using the force to get back inside.  

How did so many bad scenes get through? 

If some of the issues with episodes 7 through 9 related to the change in directors, there were overriding influences. One requirement was that Kylo Ren must be redeemed.

That may have been the least believable part of his arc.

Darth Vader always seemed to be very in control. He kept trying to bring over his son, but that wasn't going to happen. That he eventually decided he would rather kill the Emperor than Luke (which also saved Leia) seemed plausible. 

That he would then automatically be smiling with Ben and Yoda is maybe less plausible. I don't feel like any of the writers have thought extensively about the process of choosing light and dark and changing those choices. For what we have seen of Vader, okay, I believe he would choose Luke.

For what it's worth, I also believe that the petulant, reactionary Kylo Ren would kill Snoke over Rey, but still want to rule the galaxy. 

What was less believable was that Rey would be drawn to him, that he would get all earnest and die, and that she would feel bad about the death.

For all the things that she cared about and saw him do, there should have been nothing appealing about him. If the plausibility was supposed to be carried over by the charm of Adam Driver, that was a misfire.

(Unless all of her pleas for him to put on a shirt means that it was his chest, but I still don't see the appeal.) 

It would have worked better without the love story.

I get some of the motivations.

Ben Solo was the only child of two beloved characters; you want to believe that he can become something better.

At the same time, he has done enough bad things that a completely happy ending would be hard to earn; deathbed repentance is a way around that. 

As long as he is dying, why does he need the girl? Why does she need the heartbreak?

I have a thought on why it went that way, but it needs to be explored through a different character. That's what comes next.