We have DRM, we hate it but it's there, and it serves a purpose. If it is your intellectual property, you get to decide how it is used. And if you don't want to make copying too easy because you think that it will get you more money, that's your right.
The goal of the W3C is not to make to make a political statement about the rightness or wrongness of DRM. They are here to create standards that respond to use cases. And unfortunately, copyrighted content diffusion is one use case, and content owners want DRM.
And if you read the standard they came up with, it is not that bad. They managed to isolate the "evil DRM" part well enough without completely destroying its effectiveness. They also didn't require any proprietary component, though services can require them (that's what happened in the article).
Using WebAssembly (which is essentially optimized JS) for DRM is a terrible idea IMHO. DRM, to be effective, usually requires access to protected system components. It means that to make an effective enough DRM to be accepted by content providers (which is the entire point of the standard), we would need to give WebAssembly way to much power.