Board Thread:General Discussion/@comment-98.216.174.239-20150202232333/@comment-11188061-20150712043005

Because she's too naive. It's practically a given that she'll be manipulated by Cinder somehow, and the best way to break Pyrrha in my opinion is have her kill someone, accidental or no, to turn her completely to the dark side or too scared to fight anymore. It will scar her and her fighting style for life even if she ever rises again, which will also fit Cinder's memo of 'taking away their power, not overcome them'.