Of course, such attitude to literature is not a goal, but a means with the help of which a society of people, who can be manipulated and with no place for personality, is created.
The captain convinces Montag: "We must all be alike. Not everyone born free and equal, as the Constitution says, but everyone made equal. Each man the image of every other; then all are happy, for there are no mountains to make them cower, to judge themselves against."
If you accept such a society model, a danger coming from books becomes clear: "A book is a loaded gun in the house next door. Burn it. Take the shot from the weapon. Breach man's mind. Who knows who might be the target of the well-read man?"