"You Can't Do That!" - Does Any Artist Have the Right to Make That Statement?

An event that occurred during my first years in music came to mind the other day, and I thought that I should share it with you:
I was standing in front of a composition I was looking over which I had placed on a kind of podium in order to look over a portion I was working on at the time, when a colleague of mine, old enough to be my father, and whom I had known and respected for some years, sauntered over, looked at my music, then suddenly, and rather loudly, said "you can't do THAT!"
He was known to be less than pleasant; a rather gruff and rough kind of individual, terrorizing his students from time to time. His demeanor was overlooked because of his brilliance, and was an entity of respect and regard throughout his career.
His first name was Jesse, a leading exponent of the Schillinger system of composition, which was a powerful intellectual equation of the arts (chiefly music) and math, dealing with such pictorial approaches as geometric repetition (snowflakes, petals, etc.). The creator was Joseph Schillinger, who ultimately influenced such people as Gershwin (actually, Gershwin studied with him longer than with any other creative entity, I believe), the renowned arranger Glenn Miller, Oscar Levant and many other musical luminaries.
Now Jesse was an expert in the Schillinger system, and for him to make such a statement to me rather shook my world for a moment, as I had a high regard for him.
I once performed his wonderful arrangement of the " Spellbound Concerto," music written by the movie composer Miklos Rozsa, for the movie classic "Spellbound." I remember that the subject of Jessie's rancor was a group of chords, built upon fourths, rather than thirds, and he was rather vehement about the use of these chords without ultimate resolution. My first reaction was "what about the Mystic Chord upon which Scriabin based so much?"
Jesse hunched his shoulders up, uttered a kind of growl, walked away, again muttering "you can't do that," and disappeared into another room.
I must hasten to add that Jesse and I continued our friendship, as I always made a point of never reacting to his gruff tirades in front of him - it seemed to "de-fang" him.
The question DOES linger, does it not? - At least, in terms of speculation - how many said to Schoenberg "you can't do THAT" -or, to Prokofiev, or Stravinsky, or Beethoven, in his use, for example, of the human voice in the Ninth?
Personally, I am violently opposed to the totalitarian potential imbuing such a question.