I'm not sure how you make that jump. For a lot of people - myself included - buying books is a tool of convenience. I quite like having books around, but I'm not particularly attached to them emotionally and now that I'm planning on moving house soon they seem more of a liability than an asset. Going to a library is a lot more hassle than buying a book from Amazon. It's a bit more hassle than buying a book from a brick-and-mortar store (same distance, but I have to remember to return the book or I get fined, and I have to make another trip to do so.) The ability to read any book ever published at the touch of a button on a convenient device would be worth a lot more to me than 'owning' a book.
Doctrow has fallen into the trap of allowing his opponents to frame the debate. By talking about owning books, he has already implicitly bought into the idea that Intellectual Property is a sane and rational way of modelling the economics of ideas and expressions of ideas. It is not. Property rights make (some) sense for things that are scarce and have a high cost of production. For purely digital forms, they do not. The idea of applying ownership to eBooks just doesn't make sense.
They are trivial to copy, but they can't be given or loaned. Even if you can simulate the idea of giving by copying and deleting, why would you? If a hundred people want to read a book, how many of them want to read it simultaneously? Given that you can simulate moving a book between two people in a few seconds, why not just have one copy for all hundred, and copy-and-delete it to the person who wants to read it next? How many would that scale to? Maybe twenty unique copies shared between ten thousand people? Most people don't read a book for more than an hour a day, so you can easily spread a single copy between 24 people in different time zones. If they take a few days to read it, but people want it over the course of a month or two, that copy can be passed between a few hundred.
The value in a book is in the creation of the original, not in the creation of copies. JK Rowling made millions from the Harry Potter series. Any one of her readers could have created a copy of an eBook version, but how many of them could have created the original? Creativity is the scarce resource in this system, not duplication, and until you start adopting a system that recognises this, instead of trying to finance creativity by charging for copies, then you will just waste a lot of money on DRM and other tools that try to simulate expensive copying of a medium where copying is intrinsically cheap.