This essay was written with the WSJ audience (average age over 50) in mind. That audience is more familiar with the established art world and its $66B market. For an audience that grew up on the Internet like me, I would have used more nuanced language and talked more about the importance of merging the existing art market and the established art world with the more organic art communities already online.
But here's the tl;dr version of what I would have written for HN:
The Internet will grow the art market and broaden it to include artists outside of the existing establishment–the result is that more artists will be able to make a living without having to appeal to the existing system. But achieving this requires working with the established art world, e.g. major galleries and museums, to publish more of their art online for easy and free access–making art and art education accessible to everyone, not just those with the time and money to go visit in person. By moving the existing art world online, you're bringing its market of buyers and sellers with it, and exposing them to a more vibrant, diverse, and organic ecosystem that many readers on Hacker News are already familiar with. In summary, by increasing awareness and education about art history, the Internet will drive greater passion and market demand for art, which ultimately means more artists from all over the world will get discovered organically and be able to pursue their passions more sustainably.
Likewise, music has been around forever, but the chances of someone like Lorde, a 16 year old from New Zealand, seeing such success was much less likely before the Internet democratized music for listeners and creators alike. Today, it's still very rare for a visual artist to experience that kind of success if they are not part of the existing establishment. But the Internet is going to change that, and this will be a great thing for all of us.