but why would you care about copyright when your music makes no money?
Because it makes sampling extremely legally treacherous.
your music apparently has no monetary value
Almost correct. Strictly speaking, people have paid for my music. Also...last time I checked, Bandcamp had a policy where I was only allowed to offer a limited amount of free downloads and then I would have to pay them to offer my work for free. So I think it is behind the minimum paywall right now, which means it has nonzero monetary value. Which makes me a hypocrite. Shock-horror. But more than a hypocrite... I've just been too busy to check on my Bandcamp account since I went back to school. If anyone knows of a free and federated alternative to Bandcamp, please let me know.
Music, like all art and information, should be free for anyone to use and consume. Simultaneously, musicians should be compensated for their work, and I provided other ways that musicians are currently compensated for their work (merch and live shows) in the current system. Frankly , these are much more robust ways to make money.
But more accurately, everyone should have access to the resources they need to survive by virtue of being human, regardless of their success in their chosen field. Full stop.