In my opinion, it is very clear that Captain Beatty has read a lot of literature and must really care about it. I think it would be very hard to learn the books well enough to quote from them like he does unless you really like the books.
What I assume is that some few people are allowed to (or maybe required to) read the books so that they have some idea as to what they are fighting against. They need to know the enemy so they can fight it more effectively.
So I think Beatty started doing that but then kind of went over to the other side -- he started caring about the books.