Ahh, but the Deaths of Neji and Choji would have solidified the hatred of the kunoha to Orochimaru and those involved with him, Sasuke being among them. Not to mention, one of the main premise of the series is how Naruto changes people. I.E, Garaa and Neji, both characters have come a long way due to the change in outlook brought on by Naruto. Killing off Neji would have deterred from that changing of destiny that Naruto worked to achieve, and undermine our hero.