That wasn't my reading of the parent at all.
Snow White the animated film wouldn't have been made if copyright was perpetually inherited and some distant Grimm relative refused to give Disney permission to make the film. This is relevant to your original point - that "I find complaining about someone’s artistic endeavors not being free to be absurd in it’s own way." You may find it absurd, but if it were not so, a work you seem to admire might never have been produced.
There is a cultural component to art. It draws from the culture and gives back to the culture. Long copyright terms - and I find current copyright terms very long - prevent future artists from drawing on the culture to produce new, transformative works.
Disney was able to draw on cultural material from the prior 100 years to make Snow White. But if the current copyright-extension-cycle continues, it seems plausible that Disney films - and all works created in the same period - may never fall into the public domain in the USA, and future artists will not be able to enjoy the same free use of cultural source material as Disney itself has done.