These are simple terms that serve to preserve the music. It serves the interests of a third party, not the musician or consumer, if these terms are not met.
I think it serves the artist if you buy the music, however you buy it, and it doesn’t serve the artist if you pirate it.
Apply your logic to any other purchase and it falls on it feet. Do you only buy food direct from farmers? Clothes from factories? Do you only use supermarkets that use open source payment kiosks?
For what it's worth, even Richard Stallman condones the use of proprietary software on a device you don't control, like an ATM or a supermarket payment kiosk. This is not the same thing as being forced to run proprietary software on your personal computer.
I think you should talk to the artists before pirating their music and see what they think. Just deciding for yourself when it's OK has nothing to do with respect.