Supreme Leader Snoke was highly speculated on by fans when he was introduced in The Force Awakens, and a lot of people were expecting to know more about him in Star Wars: The Last Jedi—much to their disappointment. Director Rian Johnson talks about his decision to kill off Snoke and how he wanted to remove the Vader/Emperor dynamic.
Talking to Empire, Johnson explains:
"I like Snoke as a character as Andy (Serkis) plays him… He's delicious, evil and fun. But Kylo to me is where the interesting stuff is. And the notion of clearing the deck of the Vader/Emperor dynamic so that all bets are off in terms of how the villainy is going to play out, that to me seemed like a much more interesting thing. And it just seemed natural. If he had stopped in the middle of a scene and given a monologue, it would've stopped it dead in its tracks, and we would've cut it out in the editing room. This is not Snoke's story."
With Snoke gone, I think this makes Kylo Ren's redemption a lot more difficult to achieve. With the original trilogy, there was always some doubt that Vader would turn because the Emperor was the bigger bad. With Snoke gone, the only thing ultimately standing in the way of Kylo turn is himself; and I think that's pretty cool.
While some people are angry that all their Snoke theories were for naught, I think there's still a big chance that his history can be explained through the EU. Back when Return of the Jedi came out, the Emperor's story wasn't really cleared out, and for years the fans were fine with that. I don't get all this negativity surrounding Snoke; it just looks like a lot of people disappointed that they didn't get what they were expecting.
Star Wars: The Last Jedi is still out in theaters.