Fair enough. Referencing back to your original comment, if you don't believe any of work from the above names to have artistic value, then we're sufficiently far apart on the definition of the term that there's not really much more point discussing.
His point is that we (as a society) definitely consider works by Michelangelo (e.g. the Sistine Chapel) to be _definitive_ works of art, despite the fact that they were sponsored. It's a direct refutation of the standpoint that art and commercially-motivated work are entirely separate.
If an individual disagrees with that view of "society", and I agree with that individual, then just repeating that view of society doesn't really refute anything. It does however explain this deluge of people making themselves known to disagree with something they don't even understand.
