I think you're right that people simply don't know how to share, and that they probably would share if they did know how. But isn't it troubling that sharing requires some kind of special knowledge? that sharing is a "feature" to be added (or not) at the producer's whim? And isn't it troubling that people don't seem to be upset about that?
And isn't it troubling that people don't seem to be upset about that?
The fact that they're not presumably indicates that people don't lend their books to their friends all that often.
I mean, I have hundreds of books, and I've lent a couple of 'em to friends on a couple of occasions, but if I were physically incapable of doing so then I doubt it would have bothered me too much.
Paper books vs eBooks are just different products with different properties. You can read and lend paper books and use 'em as paperweights and sell 'em second hand... but you can't copy 'em, and you can't fit more than a few in your carry-on luggage. eBooks, on the other hand, you can carry around hundreds at a time, but you can't sell or lend 'em or use 'em as paperweights.