Nicholas, there is a huge difference between the way printed books are sold
and how the DRM managed e-books are sold. Yes, the content is only ever licensed, but in printed books you buy the medium and can deal with that as you wish, even reselling your licence to another - thing used book ships. However, with the DRM managed e-books you can NOT resell your licence to another, which shows even the medium is only licensed and not sold to you. Add in they can arbitrarily take the book back off your system and cancel your ability to read it, and you can see what the real issues are.