I think the comment about Picasso brings up an interesting idea. Picasso could indeed paint as well as the Old Masters, so he should be given the leeway as to how he wanted to express himself. There should be a kind of competency test on these modern sculptors. Pass it, and you would be allowed to graduate to the next level, and adopt your own style, however different it may be.

By the way, Picasso also did sculptures, but was wary of displaying them to the public. These sculptures actually helped him with his ideas on painting.