That is because prior to the widespread availability of the Internet and of PCs, only a tiny minority of people were ever expected to think about copyrights. Nobody was being sued for copying pages from a book using their pen.
Supposedly, we expect people who have no legal background or training at all to understand a legal issue that is full of nuances and subtleties. Except that in reality, nobody expects people to be thinking about that, even the RIAA and MPAA, which is why restriction systems are being deployed all over the place. Everyone knows that the average American citizen never cared about copyrights and was only buying from "legitimate" sources because there was no alternative.
Supposedly, we expect people who have no legal background or training at all to understand a legal issue that is full of nuances and subtleties. Except that in reality, nobody expects people to be thinking about that, even the RIAA and MPAA, which is why restriction systems are being deployed all over the place. Everyone knows that the average American citizen never cared about copyrights and was only buying from "legitimate" sources because there was no alternative.