[delichon]

> ... and protected from evil by the efforts of the Rangers and Gandalf. And this guarding of their innocence is presented as a fundamentally good thing.

It's easy for me to read Gandalf's motives as almost the opposite, of realizing that their innocence is a danger to themselves and including them in the fellowship not only due to the ring, but for their own growth. So it wasn't accidental that Generals Brandybuck and Took were trained by their adventure sufficiently to lead the scouring the Shire on their return, and that Sam learned to repair the ecological disaster. Gandalf was indeed protecting children from their innocence but by helping them grow out of it, knowing more of the hobbits' capacity than they did themselves.