This reminds me of a storyline on a fictional TV police drama series a few years ago.
An artist made a statue out of chocolate, and had it exhibited in a gallery. A man came into the gallery and bit off the elbow. He was arrested and charged with criminal damage. His defence was that he was merely enagaing in an act of "art criticism". The twist was that the vandal was a friend of the artist, and they had engineered the whole stunt in order to get more publicity.
In the case of the Tate artwork, it is perfectly possible that the artist was thinking of the possibility that it might be mistaken for rubbish, and was prepared for the possibility of what happened. In cases such as this, the "art criticism" (or throwing away) is to be expected, and becomes an integral part of the artwork itself.