A more serious answer. Our fathers said "De gustibus non est disputandum" because they understood, many centuries ago, that any reasoning around art is ultimately a mental masturbation. Art is art. If you get it, you get it on some other plane than the intellectual one. When you begin rationalising, justifying, and analysing too much, art ends and mental masturbation begins.
For centuries, we have called this mental masturbation "Aesthetics" and have studied it in Philosophy faculties. I mean, people who didn't need to work for a living.
But the fact remains, that Verdi or Wagner or Monteverdi (or Bernini, Borromini etc.) never "justified", or felt the need to "justify" on the intellectual plane what they were doing. Art can be judged only on the plane of art, and that cannot be expressed in words.
In short: where University begins, art ends, and where art begins, University ends.