I was reading an article that may explain the move towards window-less doors in RV units.
Although we can never do EVERYTHING to keep all people honest, it is thought that having a door with windows in them, really defeats the idea of locking a door.......regular or dead bolt. To the person that REALLY wants to get in to your unit, a quick smash, a flip of the lever, and they're in. Yeah......they run the risk of being heard, but after they're inside, there's a good chance they're invisible to most anyone else while they do what they want.
Just a thought from the writer of this article.