What they really have a problem with is the top-down distribution model. And the people heavily vested in the top-down distribution model are trying to reinforce that model as much as they can. DRM isn't a threat to piracy, because pirates will hack it. But if DRM becomes the authorized channel, then any content YOU create and distribute without DRM is by implication going through the unauthorized channel, cutting the range of your distribution- and evaporating the threat that you pose to conventional media structures.
Definitely interesting, worthwhile reading.