The problem with the article is that it's more of a rant than an essay, and, like most rants, seems to be fired by anger rather than logic. For example, how can the author have known scores of artists who had the creativity choked out of them as students? Did they somehow get their creativity back (so it wasn't actually choked out of them, but simply misplaced?) Or were they wannabe artists who now claim the creativity was choked out of them (and if that's the case, how do you know that they had any in the first place?)
There's a difference between teaching and criticism. A good teacher is priceless, even if some of the teaching is couched as criticism. Though I've never really been a teacher, I've had several good ones. And if you don't have the simple courage to blow off pointless, irrelevant criticism, how are you going to make it as an artist, even if it's only in your own eyes? I have a feeling most good artists represent what's left after the bullshit has been burned off.
As to Bernard's comment about the way of the bow, the Zen-related arts incorporate some of the harshest, most unrelenting criticism to be found in any teaching system on the face of the earth. One of the fundamentals of most Asian art systems is that the student has a lot learn before he/she can become truly expressive. A master's art might be simple, but he'd never be mistaken for a beginner. The one thing they do have in common is freedom; the beginner is free because of his ignorance, the master is free because of his learning.
Americans/Europeans, on the other hand, have in the past few decades seemed to take the view that intention is good enough, and if one is sincere about his/her art, then it's art, no matter how poor the underlying skills or how little vision is involved. I disagree with that point of view. Genuinely valuable art is the result of unrelenting work.