Aggie, I think you're right. Too many people are afraid of criticism. What matters about criticism is how you choose to deal with it, regardless of whether it's quality criticism or not. The world would have missed out on a lot of good work if everyone quit when they got their first, "Um... yeah... " response.
I try to remember that when someone gives my work that look. One of my favorite nano-reviews has been "You spent all that money on those cameras and you made that?" This was the first photo I made where I had visualized the print from the beginning and put a lot of work in it. It was a cheap shot, but so be it.
I think if a cheap shot puts you off and makes you want to quit, you were never much of an artist anyway.
ps- But it still sucks.