The Gioconda is too famous and doesn't deserve the crowd it gets? Maybe. Sounds like a subjective judgement.
People are left disappointed? Maybe. But anyone who does a 10 second search for "is mona lisa worth seeing" should already be aware of that. If they still choose to do that, why should we stop them? (or force them into an overly commercialized pen that deprives a piece of art of its dignity)
By all means, the Louvre should optimize the queuing experience. But as the author admitted, the Louvre doens't have a space capacity issue. And in my books anything that gets more people into a museum of any sort is a good thing.