The hack allow ENCRYPTED Mobi files to be read on the Kindle. So you can buy a DRM-protected mobi book and read it on Kindle.
Ebook readers have extremely high contrast/readability and are extremely energy-efficient, being able to display several thousand pages of material without needing to recharge. eBooks are a narrow product, but they have their own ways in which PMPs cannot compete.
DRM is not to prevent other files from being readable on the Kindle.
Hack let you convert encrypted Mobipocket files that were intended for another reader so that that work on Kindle.
A revolutionary portable reader that wirelessly downloads books, newspapers, magazines and blogs to a crisp, high-resolution electronic paper display that looks and reads like real paper, even in bright sunlight.