This is a big, big social issue without an easy answer. Where does free software play between the interests of the copyright owners and the users who want to use the copyrighted material with all the restrictions set by the owners?
While there are people who rightly do not want any DRM framework on their GNU-Linux distributions, there is a growing number of users who legitimately demand access to these file types.
Pino brings up another valid point that a perfect implementation of a restrictive technology necessarily means putting those restrictions in for all users, even those who choose not to partake in the copy-restricted media files.
One might say that a distribution could just strip out any DRM framework, but then would it be acceptable to use a distribution without PDF and Flash Video support? Unless you are willing to (illegally?) circumvent the digital restrictions in the specification, seems like you have to accept the DRM with the file support.
Worse, people with any stake in the debate want the restrictions in place for everyone: the copyright publishers who fanatically guard their copyright monopoly, the computer users hungry for all they can eat media content, and the developers who want to write their code to the exact specification. And while users, like Goerzen, can completely reject digitally restricted files, they can still be effected by the unrelated use of those popular file formats.
This is an issue that is going to rise up very soon specifically in GNU-Linux distributions, as both more media content is distributed with digital restrictions and more users demanding access to that media content. I perceive DRM frameworks (in both proprietary and free software) rolling out for text, audio, and video, as well as the multinational legislation and hardware solutions needed to enforce those restrictions. Scary stuff.