Well, that's how I've always seen it, as a genre for lesser-skilled authors to find publishing, but it's been so long since I've actually read a YA book that I can't remember the origin of my opinion. I just remember feeling that way.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell