Vernon didn't fail as a performer because of a lack of outside interest, he just had no ambition for it. His ambition was to turn random pieces of sleight of hand into an art, which he did.
I don't disagree with the benefit of drawing from outside sources to enrich a performance, in fact, I teach it. But, the essay's deconstruction of great performance is nieve.
Great performance is a mystery and the price is often a single minded dedication to life on-stage at the cost of all else. Nijinsky was a god on-stage; off-stage his sobriquet was "dumb dumb": lost in translation, he rarely made eye contact and would sit in the corner during parties and say nothing. It's probable that he suffered from Asperger's syndromethat one part of his brain consumed all, thus allowing him to create on an level beyond talent. Talent isn't rare, vision is. Schopenhauer said that "Talent hits the target no one else can and genius hits the target no one else can see."