The experience of reading this article is extremely disfluent. In particular, it wasn't immediately clear to me that the quoted sentences after the book excerpts were inferences about the previously quoted sentences. Instead, I read the quoted sentences independently of any context, which instilled a great sense of confusion.

However, I find this valuable. I'm going to paraphrase your anecdote so that maybe this article will get some of the votes that it deserves. Please tell me if this is accurate:

I find it easier to understand a book and make inferences about its content when it spontaneously makes me generate my own opinions. Surely there are some properties that books like these have in common. At the very least, it seems that one could purposely implant such properties in one's books in order to encourage active, independent thought by the audience.

In particular, I find that I automatically generate inferences about books that I expect to contain outdated information, and especially when the information in the book is presented in a different way than it is in modern books. As an example, let's look at a Russian undergraduate level textbook on plant identification from 1948.

It was clearly written, and didn't contain many species of plants that were discovered later or that the author considered to be outside of the scope of the book. It annoyed me when I expected the book to contain certain information that it didn't. This is merely speculation, but I suspect that the author omitted many of the species that they did because the book was intended to convey agricultural knowledge of great economic importance to the Soviet population of the time. I found the book far more entertaining to read when I realized that I would have to evaluate it in this context, even though one might think that this would actually make the book more difficult to read. I was surprised that something as simple as glancing at a note on beetroot production rates could make me do more cognitive work than any cheap trick that I'd ever seen a pedagogical author try to perform purposefully. As in Darwin's travelling accounts, a narrative grants consistency to the body of knowledge entire, and encourages inference that would not otherwise be encouraged by a barrage of declarative facts. Conversely, the pragmatic consideration of learning about the academic subject at hand encourages engagement with the narrative.

There may be other ways that books could be written to spontaneously cause independent thought in their audiences. Perhaps we can do this on purpose. Or perhaps the practice of making inferences beyond what is obviously stated in books can be trained.