So, we all know that people had issues with Star Wars: The Last Jedi. Leia's use of the force, no background on Snoke, Luke doing insane Jedi stuff, etc. I know, I have heard all your complaints, mainly because every Star Wars fan on the planet has been wailing at the top of their lungs while they are stamping their feet. "I wanted it this way! But Rian Johnson made it that way! It's not fair! I'm gonna be first in line for the next movie so I can talk about how terrible it was before aaaaaanyone else."
Seriously, that's what you sound like.
Anyways, if I was Rian Johnson, I wouldn't answer anything; he made a movie, and he absolutely deserves to just sit back and let the movie speak. In this day and age, everyone has to respond to everything, but the problem is, any jackass with an internet connection is suddenly a powerful orator, who demands an answer to his or her query. Johnson keeps explaining his plot points over and over, hoping everyone will finally get it, agree with him and decide his movie was amazing, not terrible, as so, so many people claim it is.
Many people figured the Knights Of Ren would play a big part in this film, after they were teased in Star Wars: The Last Jedi. That turned out to not be the case. Rian Johnson explained why in a recent interview on the Empire podcast.
"I guess I could’ve used them [the Knights of Ren] in place of the Praetorian guards but then it would feel like wasting them because all those guards had to die. And if Kylo had some kind of connection to them it would’ve added a complication that wouldn’t have helped the scene… Truth is, I just didn’t see a place for them in the movie."
There you have it kids. Basically, if he would have added the KoR to the film, they all would have been slaughtered, and then everyone would have been talking about what a huge missed opportunity it was, and what an idiot Johnson is, etc. Now that Ren is the new Supreme Leader, I think it's going to be awesome to have (hopefully) the Knights of Ren running around as Kylo's personal gestapo squad. A group of evil force-users, all trying to impress their "daddy", Kylo? That sounds like good cinema to me.