I suppose Keith Barry's magic show was entertaining, though far from exceptional. But TED audiences expect more for their money than to be simply entertained. They are expecting to learn something. What were they supposed to learn from Barry's performance?
Art causes even more problems than it solves, when it questions foregone conclusions and assumptions. And unlike assembling a chair, there isn't one way to do it right and you can't know what it's going to look like by studying the box.