Maybe it was like Leia said long ago - that there was too much Vader in him. It was the yardstick by which Kylo Ren measured himself and the First Order gave him the means by which to do that, to be that. More importantly, there was power. People like Finn had nothing to gain. He did. The Supreme Leader promised him everything. Everything.

And yet, he still felt goosebumps when they made the jump to hyperspace...

"You pride yourself on closure. But you still call me by that name..."