So, as part of the online writer's community Forward Motion and also as a high school teacher, I've had to balance my two critics. Inner critics, I mean. On one side there is the sharp-clawed, impatient, catty critic. On the other is the calm, patient, tactful critic. I try to keep the first on a tight leash. Especially in the classroom.
However, with critiques, I find that I'm unable to be tactful unless I first let all the snotty, potentially damaging comments out first. So my first pass through a work to be critted has been known to have notes like "Are you completely stupid?" "Do you think I am competely stupid?" "Fucking A, heard of grammar?". You know... all the stuff you say to yourself when you read something in need of serious help... or a good bonfire. But presumably, the person who has posted their work for crit knows that it's not perfect, so you don't actually want to rub their face in it. (There are exceptions.)
Obviously, the catty comments are the easiest, floating so close to the surface as they are... Meow meow meow meow hsssssss. So it usually turns into a scenario of my responsible, tactful critic beating the living shit out of the evil kitty who then sinks its claws into the teacher's ankle and purrs while teacher tries to comment nicely.
No wonder I'm getting burnt out in the critting arena. I figure I have a good six months before I need another hiatus.