That's because the analog market has natural logistical limitations for copying and improvement.
I cannot OCR a paper book I own, make modifications to it and then publish it on the web. Nor can I photocopy that book and give it to friends.
Re:From Linux to OSX - 1 Year Later
by chimeracoder on Monday September 10, 2012 @12:38AM
(#4498336)
> natural logistical limitations for copying and improvement.
There's also a marginal cost beyond the first unit, whereas for software, there is none.
> I cannot OCR a paper book I own, make modifications to it and then publish it on the web.
You'd be violating a copyright, which is a separate point of discussion, but I'm talking about the physical book itself. You've sold me a bunch of paper bound together, and I'm allowed to modify (or destroy) it, as well as resell it to someone else.
But outside of real estate, I can't think of any analogous practice outside the information market - you don't sell me a book on the condition that I not loan it to a friend, write notes in the margins, or even burn it.