I certainly don't intend to
devalue creativity. Like many (most?) on HN I have a career where I get paid for my creative work.
However, creative outputs are qualitatively (and legally) distinct from physical outputs and to pretend otherwise is only going to be a hindrance in properly creating a system to nurture cultural output.
Let's start with the car example. I can buy a car, modify it and resell it. I can buy a cassette, modify it and resell it. Legally I can't buy a digital download, remix it and resell it. There's already a difference here.
If I come up with an improvement to someone else's car design, am I allowed to print up one for myself on carwhale? Am I allowed to sell the new design? Am I allowed to describe my changes to someone else? Where do we draw the line? 100 years after the first car is printed from car-whale, does the estate of the person who designed the base model that the cars we are now printing hardly resembles still get royalties because the design before the design before ... the design before happened to use their car as a quickstart convenience?
With physical objects it's clear. The person who built the car gets paid once and we don't have to debate 100 years later over ship-of-theseus questions. With creative outputs its far less clear.
Just because we agree that it is a Good Thing for creators to be rewarded for their work doesn't mean that copying their work is equivalent with theft. It's its own unique thing and coming up with a framework to handle it correctly is quite challenging and to just say "digital theft is still theft" is a way to ignore those challenges rather than trying to meet those challenges.