You can't kill him off because Pike was in an Episode of TOS called "The Menagerie", he was clearly never demoted, although seriously injured in some sort of accident where he sacrificed himself to save others he was paralized and stuck to a wheel chair. To kill Pike off would create a big plot inconstancy. If they tried to do with Trek what they doing with Superman (i.e. forgetting some of the episodes or movies) I will refused to see such movie.