I didn't say the current system worked well, but neither was the parent post critiquing just the current system, but "purposeful restriction" in general. Accuracy matters.
I'm curious about the argument that is framed with "it presumes the unnatural (even if useful/positive) present state of copyright as a naturally occurring thing."
I don't think this should be discounted so quickly. Nothing in this domain — money, private property, laws, justice — are obviously naturally occurring things. One of the great traditions in the effort to understand how rights and value come to be is the creation of narratives that connect the rights to early natural states. We see this in Locke, Rousseau, Rawls, etc. You could just ask the question of whether the current state "works well", but then you are in the wheelhouse of Jeremy Bentham and other utilitarians. Fine, but so far these kinds of arguments don't lead to worlds many of us like.
I submit that intellectual property is absolutely less natural than e.g. real or personal property. I haven't done a deep dive, but I'd strongly wager that if you did a sweep of traditions of property across times and cultures, you're going to find a LOT more uniformity over the idea of property rights over PHYSICAL THINGS like land and food (and probably money or other forms of exchange? maybe not) than you will IP.