ebooks have texture, color, they can make sounds, you need to interact with them to move. What you think of are toys, not books.
But I maintain books have far more physical qualities than any tablet or e-reader. Variety, for starters. Tabs and e-readers all come in some shade of black or gray, they all present a very similar glass texture to the touch, and they only have that new gadget smell for two days. On the other hand, very few books are the same. Moving from a magazine to a hardcover to a paperback may be all the same for you and me, but for a 6 year old is an extremely important feast of sensations that informs her developing mind about the myriad materials and textures and smells the world is made of.
Why rob a child of that variety?
Keep in mind, this isn't saying ebook readers are suitable for everything. No ebook reader, at the moment, can match a huge, colourfully printed kids book, not to mention their fragility and price isn't suitable for kids. The same goes for feelies, pop-up books, cards with animals, or colours or other such educational toys, and so on. Take those out of the equation, and there are no advantages for print over digital. Actually, there is no advantages for print over anything if those are taken out, since a child will just refer to them as yet another toy.
removing books 'robs a child of a variety'. I think not.