I met Joshua Bell once. He was my girlfriend's roommate's boyfriend's roommate. No, really.
Brother Timothy Marie shares this
Two differing sample base invalidates the experiment. People travelling through busy public spaces are not people who are seeking fine music.
Facts Not Lies
Carlos Santana did similar experiments with better yield in cash...

He also sat as a beggar outside some of his concerts.

Not quite the level of excellence as Joshua ... but a level of excellence in his own right.

During the concert he would express dismay about people (singling out none)... never telling them he was actually witness to their indifference.
Ave Crux ignoring the God Who lives within us offering us Eternal Life from moment-to-moment, awaiting our love for Him. For, even now we can begin our Eternity of intimacy with Him... But so many race about their lives without pausing to consider it, or endeavoring to enter into that eternal "Face-to-face" begun even now.