I think you attribute your own goals to the DRM. I, for one, don't believe DRM is there to prevent all and any copyright infringement through technical means. It works very well against casual copying. Even Macrovision for VHS did, despite being cracked. It has no means to prevent e.g. unlicensed public performance though. Neither it's aiming at preventing unlicensed distribution on non-DRM platforms, which you seem to point as a fault of DRM.