Linux is probably an exception, and not the rule, and it is such an exception that large companies are willing to subsidize it. I've been looking for some good sound editing software, and the only solution I could find that was good at altering tempo without creating weird artifacts was closed-source and proprietary. I've also rarely played any open-source games that were as good as the closed-source ones.
The point is, if someone does something that creates value, they should get compensated somehow. Asking musicians to produce music for nothing more than the sheer joy of it is exploiting them, and impolite, besides. If someone gives you value, you ought to give value back. I don't agree that the RIAA's way of getting back that value is correct, but that doesn't mean that copyright is a bad idea.