While that choice of words, "not worthy of praise" may have sounded somewhat harsh so some, I must say, that was a REALLY powerful statement to say.
I do agree that real good criticism is saying what you liked about something and what you didn't like about a certain work, idea, etc.
And I think it's typical more for a young person to be offended by criticism. I suppose they just need to experience life more in order to take criticism.
I used to be unable to stand constructive criticism. When I was at primary school I was so addicted to praise that any suggestion that I could have done better on something drove me to the edge of tears (or far beyond it).
So was I, and...I guess I still am.
I'm trying to work on it though.