Once again (another time <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" /> ) I must agree with Kiya ... <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />
Criticism can be an art : Put so much criticism into it that the criticised one will understand, but also put so much love into it that the criticised one will gain power from the critique.
Another way would be to criticise someone without mercy - the person learns then, too, but the intension is a completely different one.
The latter one could induce the result : "Being criticised is weakness !" thus perhaps leading into emotionless perfectionism.
The fist one could induce : "Being criticised is a chance for making it better !" Thus enhancing ones works meanwhile still being able to put the whole heart into a work.
That's my opinion.