David Lowery made this point in a much more compelling and complete way:

https://news.ycombinator.com/item?id=3850935

Of course, ultimately, people are (rationally) compelled by the own immediate interests. That's what allows people to deride musicians for trying to "cling to obsolete business models", as if a verdict on the viability of someone's business model entitled people to ignore their rights. So I don't expect Roger Waters and David Gilmour to have much more luck pressing this argument than any other musician has had.