Thank you; I think you answered my question.

Basically, in software, you can choose to open-source your software as marketing if you want, but proprietary is still a sustainable business model. The claim here (which I am in no position to evaluate) is that for music, you no longer really have any choice: selling music itself is no longer a sustainable business model; you can only give it away in hopes that you can sell something else as a result.

That is pretty depressing.