It also makes the Xel'Naga artifact an even worse plot device. I could understand needing a magic gizmo to cure Kerrigan from the Zerg infestation, if that was the route they would have taken. But if she maintains her connection with the Zerg, then the only point was to change her alignment - to 'de-evil-ise' her. And that would have been much better accomplished by using character development and the stories of Raynor, Mengsk and Kerrigan. Until Wings of Liberty, the exact nature of Kerrigan's freedom - whether she was still free to be who she had been or whether she had been transformed physically and psychologically - was ambivalent. If this is the route they wanted to take, they could have instead swung the verdict on the side of freedom and forced a change of heart on her through character development rather than magic device.