I have to agree with FlorenceArt's disagreement. Wait. . .what?!?
I didn't want to quote her whole post, though. The problem with relying on documentaries is that you don't know what the editor left on the cutting room floor. At least with a book, if you are reading the facts, you can come to your own conclusion rather than the conclusion the documentor (?) wanted you to conclude. The Al Gore documentary comes to my mind first as an example. Although a book can be slanted towards the author's viewpoint, there tends to be a greater amount of statistics and facts presented which you can then verify.
About whether reading or escapism reading can be a bad thing, if something, anything really, is done to excess, of course it's bad. There needs to be a balance. One of my mother's favorite sayings (and she had quite a few) is, "All things in moderation."