They author fundamentally misunderstands art: “The value of artistic work is in reaching people.” They claim repeatedly that artists have an obligation to use commerce to spread their work far and wide: “Can you not see that in denying the syndicates profits that countless others were harmed?”
It is a long elucidation of exactly what Watterson has spent his life trying to avoid. It’s literally calling the man “selfish” for refusing to allow others to profit from his work. It’s kneeling at the altar of capitalism and kissing the ring of commercial exploitation, and prizing both those things above simple human creativity, and the ability of artists to curate their own works.