You should really read Jobs’ essay in its entirety, but here’s one other passage from it that’s worth highlighting (this one immediately precedes the one I quote below):
The second alternative is for Apple to license its FairPlay DRM technology to current and future competitors with the goal of achieving interoperability between different company’s players and music stores. On the surface, this seems like a good idea since it might offer customers increased choice now and in the future. And Apple might benefit by charging a small licensing fee for its FairPlay DRM. However, when we look a bit deeper, problems begin to emerge. The most serious problem is that licensing a DRM involves disclosing some of its secrets to many people in many companies, and history tells us that inevitably these secrets will leak. The Internet has made such leaks far more damaging, since a single leak can be spread worldwide in less than a minute. Such leaks can rapidly result in software programs available as free downloads on the Internet which will disable the DRM protection so that formerly protected songs can be played on unauthorized players.
An equally serious problem is how to quickly repair the damage caused by such a leak. A successful repair will likely involve enhancing the music store software, the music jukebox software, and the software in the players with new secrets, then transferring this updated software into the tens (or hundreds) of millions of Macs, Windows PCs and players already in use. This must all be done quickly and in a very coordinated way. Such an undertaking is very difficult when just one company controls all of the pieces. It is near impossible if multiple companies control separate pieces of the puzzle, and all of them must quickly act in concert to repair the damage from a leak.
Apple has concluded that if it licenses FairPlay to others, it can no longer guarantee to protect the music it licenses from the big four music companies. Perhaps this same conclusion contributed to Microsoft’s recent decision to switch their emphasis from an “open” model of licensing their DRM to others to a “closed” model of offering a proprietary music store, proprietary jukebox software and proprietary players.
This echoes a point I’ve made before: there is no such thing as an open DRM standard. By definition, an open standard is available for anyone to look at. And by its nature, DRM requires that at least some details of a DRM standard be secret, which means that it cannot be open. “Open DRM” is simply a contradiction in terms.