With respect - copyright's protection of income is the point

That's, by design, the tool used to encourage people to invest their time into producing works.

We would not be having this conversation at all if people weren't able to make money of these works - there'd be no point to copyright at all if there wasn't money to be made (by the artists) and the reproduction of their works wasn't restricting their ability to generate that income (for themselves, or their agents).

I want to emphasise that I am not arguing in favour of the system, only how and why it works this way.

> That's, by design, the tool used to encourage people to invest their time into producing works.

The tool used was control over distribution. If income was the point copyright law could just hand tax payer money over to anyone who created something. That'd guarantee income instead of the system we have which allows artists to invest in the creation of a work and still never make a dime on it. Ultimately though, I do see your point and I agree that making it possible to earn enough money to justify the creation, publishing, and distribution of a creative work was a large part of the intention along with the establishment of the public domain.

I probably should have phrased that as "The point of copyright isn't to protect income until the work is no longer highly profitable"