Sometimes this requires the authors to have pretty thick skin.
I wouldn't ask anybody to say anything that was untrue, or praise a story that is not praise-worthy, but I do hope everyone will remember that this is the CoW contest and therefore may have a higher percentage of young or new writers than, say, the pseudopod contest.
I would feel particularly badly if I completely savaged a story, only to find out later that it was an earnest teenager submitting his very first story.
(That being said, I try never to completely savage a story anyway, because even grizzled veterans with steely-eyed gazes and solid platemail for skin don't deserve to be savaged!)