Ow art becomes not-art? (based on given article)

Read the article This is Not an Artwork at this link:
11/what_happens_to_art_that_gets_damaged_no_longer_art_at_columbia_reviewed.html
Your opinion:
Can damage to an artwork make it not art? Can a declaration by insurers make something not art? If art has no market value, is it still art? Is there any way in which an artwork can cease to be art? Discuss!