What if their mother really was a hamster?
I agree critiquing is a two way street--the writer needs to put their best baby forward (or at least the basics, like spell checked and punctuated) and the critique-er needs to approach said baby with a firm, but gentle hand. Don't want baby to fall off the changing table, but you also don't want baby to have diaper rash. Or for those of you with furrier babies, it's like trying to force feed a cat that nasty hairball goop without causing a cat-tastrophe.
Forgive me, I haven't had enough coffee today.
I have great crit partners that don't mince words, but they also tell me what is working and what is good. All negatives can be demoralizing, but to be a writer you will have to face serious attacks on your work--not everyone is going to be your cheerleader and the faster you realize that it's not personal, the better your work becomes.