Well, this is part of the problem.
Sometimes "the author's labor" amounts to reordering questions at the back to mark it as new revision and charge 150+ usd for a book that should have been $20 brand new, and is only purchased because it's a required title in a required class to get a piece of paper required for employment.
In that case... Fuck yes. Screw the author's "labor". Arguably, screw the whole damn system.
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Copyright rarely helps small authors who actually need it.
It usually gets employed by conglomerates that own distribution and are already screwing authors as hard as they think they can get away with.
It's genuinely a pretty terrible system in its current form.
We can do better.