It's completely innapropriate. COMPLETELY. There may or may not be a time and place for concrit--and I agree, that time and place is generally when it has been asked for and is relayed in private. I realize that I differ from the large majority of fandom in thinking this and I know that people believe that if a story is placed in the public eye it is open to that which comes at it.

That said? A fest where people are writing stories from prompts that other people have given them, attempting to best fill those prompts and everyone is anonymous and clearly has not granted consent to be given concrit?

NO.

There's no other word for it.