"Someone writes their travels down in a journal, it winds up in a bookstore, someone else buys it. It's the original, not a copy. In a world with the printing press, I'd expect handwritten books to be unique originals or elaborately scribed copies. The history book didn't look like the kind of high quality scribing and whatnot that would make sense as a nice luxury to stand out against printed books, which is the only way handwritten copies can compete with printed books. Handwritten originals can compete, because they're unique, or even if copies exist there's an appeal to having the first one. But copies? Not a chance, the only way handwritten copies survive in a world with the printing press is by being luxuries. So we've got no printing press here, which means if we build one we can sell it to the publishers and make hideous piles of money."