I read it differently, but I don't think the author was saying art has no quality in the way you're interpreting it at the end of your sentence, in the sense of value or anything to offer. I interpreted them to mean that there's no way to objectively determinine that value, so practically speaking there's no objective quality in art. I think there's even a sentence or two where they try to make clear that they're not questioning art's value, just our ability to determine that value in real terms.

I agree that the author's choice of words was probably kind of poor. But I interpreted the article to mean that as it becomes more difficult to determine inherent worth in an area, success becomes more and more dependent on social networking effects per se. If you need a hammer, it has a specific function, and you can quantify that function in various ways. But if you're talking about something where the value is unknown, either because no one knows the ultimate truth, or because it's based on subjective experience or something, you can't quantify it, so you go back to networks.

This author has been making the rounds a bit in the last few years, and I think they've done research on these topics. Their argument is that network effects are very strong, and account for a lot of variability in outcomes that are popularly attributed to individuals (broadly defined).