this message may be offensive
Personally I don't think people are looking at Kylo's story in quite the right way, the way I see it Kylo was trying to be something he's not, when Luke tried to kill him Snoke/ Palpatine had already started reaching out to Kylo through the force, think of the influence of Snoke and Palpaitne as a nail and Luke trying to kill Kylo as a hammer, being filled with anger and hate after Luke tried to kill him Kylo gose seeking Snoke, (what I say next isn't confirmed but it's safe to assume) In his younger years Kylo more than likely idolised Luke in a similar way he dose Darth Vader as seen in the new trilogy, so after seeking out Snoke that's probably when Kylo's admiration for Vader grew.
If your only a casual fan of star wars you probably don't know that masks and helmets of dark side users can contain an essence or a type of echo of their dark side presence, in The Force Awakens Kylo states that he feels the pull to the light side, he them goes to Vader's mask and meditates to reconnect with the dark side, this shows that Kylo is having to force himself down the path of the dark side and not to mention that Palpaitne was still influencing him and Kylo kept feeling the pull of the Light and when he killed Han Solo that further creates conflict within him, even Snoke acknowledges this.
Kylo has shown that he isn't just some black hearted villain, he's a complex character who because of the events in his life and the manipulation from Palpaitne lead him down the a path that never truly was his own and so when Rey heals him with the light side of the force it allows him to finally break from Palpaitnes subtl influence and decided to be his true self.