Free, instantaneous distribution of all music as soon as it is produced (an exaggeration of torrents, but not by much) seems to take away the right to pursue a profit, at least profit by distribution of recordings.
Or perhaps there is no right to pursue profit by distribution. Perhaps there is only a right to pursue profit by live performance. But what happens if that becomes copyable? We already have at least one instance of a holographic singer (see https://en.wikipedia.org/wiki/Hatsune_Miku). What if holographic recorders and projectors become as cheap as cameras and microphones and screens and speakers? Live performance could be copied about as effectively as live sound is now (recorded music is not a perfect reproduction of what was played in studio or on stage). What then?
Is there no right to pursue profit by live performance either? Decreasing costs of production seem likely to make copying merchandise reasonably possible (you can already just draw a design and have someone print a T-shirt or such for you). So is there no right to pursue profit by merchandise either?
If there is no right to pursue profit by distribution, live performance, or merchandise, I think it is safe to say there is no right to pursue profit at all. But is that really fair? Musicians don't even deserve the right to try to get people to buy their product out of anything other than sympathy?
Frankly, I think pay-what-you-want is great. But I don't think it can provide the same level of economic activity and technological development we are used to. The most advanced personal computing company in the world is also the most closed or near it. The iPhone, iPad, corresponding retina displays, the Macbook Air... all produced under tight control and for direct profit only. Why isn't an open, pay-what-you-will hardware company beating Apple? We all like our i-things, so why aren't we paying people to develop them? Why is Apple's cheapest product $129, and the cheapest Kickstarter level usually $1? Why won't we pay $129 for Kickstarter projects that sound interesting to us if pay-what-you-will really works?
Similarly, the most advanced synthesizers, digital mixers, even music software are all produced to be sold. Why is there no open, pay-what-you-will synthesizer to match Kurzweil?
Why is there no open, pay-what-you-will library to match O'Reilly's? Why no open, pay-what-you-will coffee to match Starbucks? Why no open, pay-what-you-will transportation system to match the U.S. interstates and European and Japanese light and high-speed rail?
I would argue it's because accepting only the payment you can convince people to offer voluntarily doesn't work in most cases at an advanced level.
And either way, it doesn't seem to right to force people into a pay-what-you-will model.