That doesn't change the technological harm of DRM. Putting a DRM-shaped hole in web standards makes browsers less secure, less stable, and less maintainable.
iTunes copy protection used to be broken in a few hours, Blu Ray is long since cracked. DRM is neither secure nor cryptographically sound ( http://craphound.com/msftdrm.txt ). The business models that work online keep on being built without DRM.
But DRM remains an irresistible fantasy for corporations who haven't worked out the economics of getting Apple, Amazon or Netflix to add locks to their content.
That's similar to saying words don't communicate well.
It makes no sense to say that DRM is cryptographically unsound - for the very reason you state, DRM is not a technology.
There have been non-optimal algorithmic choices and weak key-management, but those are entirely separate from saying DRM is cryptographically unsound.
This goes (if I'm not mistaken) for the Screen, HDMI cable, GPU and OS. It's a hard balance between keeping consumer happy with their choice and only accepting compliant and capable producers.
The downfall of the DRM is either going to be stripping the legal protections, or competitors without DRM being able to offer a better experience. Sadly, whilst cutting DRM gives a massively better experience, it comes at the cost of control over the customer. I think Netflix really doesn't mind that I can't watch Netflix on Plex. Heck, they might even prefer that.
This is what really scares me about DRM, it enables the building of walled gardens for much more than just media content.
This is what video DRM will need. For games, where each game has a somewhat customized version of DRM, taking a few weeks to break is good enough. For video, this will give you a few episodes; but once it is broken it is broken for everything until you roll out a new scheme. Overtime, I would expect the breakers to get more efficient and automated at breaking schemes, while the DRM makers get increasingly lazy and complacent.
People ideologically opposed to DRM tend to have two blind spots about the DRM service model.
First, they assume that DRM users demand that DRM prevent any copies being made. But that's not true: obviously, any video you show a user in the privacy of their home can be cam-copied. It has even been the case (though it will be less and less the case moving forward) that you could obtain a high-fidelity digital copy. DRM users have always understood that to be the case; what's important is not that copies be impossible, but that they be difficult for ordinary users and, ideally, incur a quality hit. If copies are inconvenient and/or of lower-quality, most of the market will pay for legitimate copies.
Second, and more importantly, DRM opponents assume that the restriction DRM users are seeking is indefinite. But for the most part, content owners are much less concerned about long-term restrictions than they are about the new-release window when their content is most in demand. A DRM scheme only has to survive for a couple weeks to generate immense value for content owners.
From a security and cryptography perspective, a scheme that can be resilient against expert adversaries for a few weeks, or even a framework for minting such schemes on demand, is a commercially reasonable proposition.