If an art teacher is not acting professional thats not...
At school pieces of art work shouldn't be graded/levelled
I have a very close friend, she draws amazing. She now started going to this art class (not in school) and she came back to me and she was very lightened up. In their art class they were told to bring something they had created, and the art teacher showed them how to make it better. He taught them painting techniques, and how you know where to put more shadows and such things. The painting she brought back after class was a very improved version of the original one. If an art teacher is not acting professional thats not ok, and they should be changed, but that is irrelevant, unless you want to see that all art teachers are incredibly unprofessional, which is highly unlikely. And I disagree with you that there is no wrong in art. Art has "fashions" times where specific kinds of arts are more accpeted and others less, some art is timeless, which is usually if you draw a painting very true to the actual thing you were capturing, nearly like a photo, it will always be amazing and treated well.