I don't care about DRM as long as it's lightweight and seamless. Streaming is one use case where its use is entirely justifiable if it operates transparently.
As long as streaming is available on all the devices I wish to use it on (that used to include Linux, but nowadays it's not my "daily driver"), then I'm okay with transparent DRM for streaming or rentals, too.
If a platform has to be explicitly supported in a supposedly cross-platform standard, then the details on how to implement that must be published or the standard is no longer cross platform.
With this move, Linux is no longer "supported" on a web wholly built on it. That's completely fucked up.
DRM is fundamentally incompatible with the web. Let's not give it any reason to think it belongs here.
The problem is most companies wouldn't create modules that are compatible with all operating systems. Open web is supposed to be open, not platform dependent.