by StarlightLioness » April 10th, 2011, 10:25 pm
I think it had several reasons. First, the writers obviously wanted to press the "Kovu-looks-just-like-Scar" envelope and give him a matching scar on his eye. So we have the "You've killed your own brother" rage that Zira has. In her rage, she strikes Kovu and gives him a scar. The scene also drives home how self-centered Zira is and how little she regards Nuka. Sure, she has a tender moment as she cradles his head as he dies. But then, she turns around and says "Simba has hurt me for the last time. Now he's corrupted Kovu." Not a single mention of how upset she is to lose her oldest child.
On a more subtle note, I think Nuka's death serves as the only reason why Vitani sees the light and sides with Simba and the Pridelanders at the end. "Kiara is right." I think seeing her brother die in a lost cause (trying to get Zira's love and attention" and seeing her mother dismiss his death (again she is hurt not because Nuka is dead, but because Kovu has sided with Simba) pushes her over the edge. And it is only after Vitani switches sides that the rest of the Outlanders do - they've already witnessed Zira dismiss Nuka's death, but now they witness Zira tell her only daughter "Then you will die as well."
So Nuka's death causes a snowball effect, and eventually causes the Outlanders to abandon Zira and side with Simba. Without his death, the prides might not have been united - or if they were, unity would have been achieved only through a lot of bloodshed.
"Simba, let me tell you something my father told me. Look at the stars. The great kings of the past look down on us from those stars. So whenever you feel alone, just remember that those kings will always be there to guide you. And so will I." ~ Mufasa