[shmerl]

I think it's mostly about practical implications, rather than legal ones. Legal battle is about those who push some junk in the law vs those who attempt to repeal DMCA/1201 and etc (and that can take quite a long time to achieve). But practical battle goes about simply adding more DRM everywhere vs getting rid of it.

Companies of the RIAA/MPAA style don't operate with common sense and pure logic. Practice demonstrated it multiple times. They are driven by random impulses like paranoia, lust for control and so on. So don't expect them to give you a logical answer why they don't use DRM in music, but use it in video.