Han Solo's death was an incredible scene, and one of the things it did was properly setup Kylo Ren as the villain of this new trilogy, the big enemy to go up against our new heroes. He may have fell the pull of the Light in the novelisation, but ultimately, he's made his choice. No doubt it was incredibly hard, but it's done, and now he'll be trained more in the ways of the Dark Side. So really, there's no way he should be redeemed. Yes, Anakin was, and he killed younglings and Obi-Wan and all other sorts of monstrous things, but from the moment he was presented as being Luke's father, there was the possibility of him coming back to the Light Side, and it was achieved thanks to Luke. That possibility existed for Kylo Ren. And he could've came back thanks to Han. Instead, he killed him. And whatever the precedent for redemption in Star Wars, you don't come back from killing Han freakin' Solo. Unless, of course, you do?