I'll be honest, they kind of suck. But the truth is, they're necessary if you're like me and can't quite see your failings as a writer all on your lonesome. And the ones that suck the most? Well, they're the ones that will help you grow. No one likes to hear that their writing isn't up to snuff. That it's just not good enough as is to get the attention of an editor, but it's often the truth. The great authors of our age very rarely entered the writing world fully formed and ready to knock your socks off with a great yarn. Writing is a craft you grow at, just like art, or even baking. That first half burned slice of toast and punctured egg you made when you were four is most likely not the epic wonder of your baking career. And that totally awesome story you wrote in high school. Well, it's kind of like the toast and eggs (at least if you're me).
The important thing to remember is that the critiquer (or at least any good one) is not judging you. I know it's hard as an artist to separate self from work sometimes, but it gets a lot easier once you do. Just because one story flopped doesn't mean you're worthless. It just means you need to get up, dust yourself off and rework your story. Or let it go die quietly in a corner while you move on to something else (I've had to do this before). You write another story, and another, and hopefully each one is a little better than the last (and if not, you can always send it off to keep the other quietly dying story company). The name of the game is improve, improve, improve.
Which, quite frankly, won't happen if all you ever hear is how great you are and how good your story is. It's nice to hear, but it's not what's going to propel you forward. (At least if you're me. Maybe you're lucky and still feel like pressing yourself to become better when all you hear is how you're the next best thing to sliced bread. I'd just find it a little hard to buy.)