It was an analogy, and not an attack on developers like it seems some are taking it.
I was going to write how the invention of the printing press democratized book-making so that books became more widely available, and wasn't just in the hands of monks and scribes as was previously done. Though yes, anyone could have taken the time to hand copy their own book if they were so inclined and had access to one they could copy. But the printing press and copiers and word processors and computers have made the process so much better and widespread.