Honestly, the 'discussion' about this topic over on /r/books was one of the craziest things I've ever seen on reddit. (Though to be fair I do avoid the more WTF subreddits.) There were anti-public domain people just calling everyone self-entitled thieves. People insisting that adaptations had no merit anyway so public domain wasn't necessary (even though many of Shakespeare's plays are adaptations). And speaking of the Bard, one person pointed out that being in the public domain contributed to Shakespeare having the longest writing credits on IMDB, that rights costs are an issue even for studios with a budget, and that public domain was more than just about reading books for free (what the grandparent comment in the discussion was claiming). The comment seemed to do okay upvotes-wise, but anti-public domain people couldn't help nitpicking. People argued that adaptation rights are the smallest line item in a movies budget and that they are the same as the cost of a mid-sized sedan!? One person even tried to insist that Shakespeare only has the longest writing credits because he's Shakespeare, the best writer in the English language, as if dozens of adaptations a year would still exist if people had to pay to adapt his works!? Said commenter flat out called the poster of the Shakespeare public domain comment an idiot and claimed that next the person would say that using modern day clothing for costuming is a cost cutting measure! In reality, modern day dress versions of Shakespeare are a cost cutting measure, just look at Wheadon's recent Much Ado About Nothing for a cinematic example, or damn near every YouTube adaptation of classic literature for a even lower budget example. I won't name this particular commenter, but they post under their real name and are a 'creative/artist' type if you look them up, which makes there arguments even more absurd.

That discussion makes me wonder how public domain advocates should frame their arguments for people who insist we are just thieves and that culture belongs only to the artist and their direct descendants forever?