This is a terribly misguided and misinformed post.
DRM has nothing to do with the agency model. You can have DRM with or without an agency model. DRM existed on e-books long before the rise of the agency model.
The iPhone does not require DRM and many books from iBooks store don't have DRM on them. In fact, in most cases the ONLY reason why an iBook cannot be used on a Kindle is because of the Kindles non standard file format (without first converting it).
Jobs pushed for the agency model on books to eliminate Amazon's stranglehold on e-books. It was attractive to publishers. Nothing more, nothing less.
(It is true that by eliminating Amazon's stranglehold on books the price of e-books rose because publishers could set their own prices. Amazon has responded by by-passing publishers and trying to get authors to self publish books on Amazon. So it goes.)