Saving his voice. I remember one singer a couple years ago who was famous for screaming the particular line of a song, and she said she had to stop screaming because she wasn't able to sing anymore.
I'll take a voice and no scream, than a scream and no voice.
Though I agree -- that scream is one of the highlights of the song.
EDITED: Aha! I remember! It was Tracy Bonham and the song was "Mother Mother," with her chorus "Everything's FINE!!!!"