DRM is more about having leverage over the provider of the playback device and casual piracy than it is about protecting the content against hardcore piracy.
The problem is that in most case it doesn't. Like in the example from this post, where users can no longer run fully open browser. Or when you buy a game and are unable to play it because your internet link is down. I have never seen a DRM system that wouldn't impede honest usage in some way.
