I am always a little sad when I hear someone being steered away from a classic that has been illustrated for children.
The reasoning behind this seems to be in seeking to develop the inner eye (imagination), and appreciation for the language itself apart from the distraction of images.
On the very small chance that anyone reading this post holds that view, here is an analogy: Illustrations (when they are something the child is actually interested in, mind you) are very like bath toys.
There is an age when the water itself ceases to be infinitely entertaining and tub toys become a very motivating factor in continuing baths.
Pictures can serve the same purpose, holding the child’s attention long enough for us to pour the words over them and whet their minds with new phrases and ideas.