I'm not 100% clear on the technical side of this but according to the article, in order to implement the 'standard' you require permission from the entertainment companies as they control the CDM. So they're the gatekeepers. Is this incorrect?
The trick, which EFF points out, is that CDMs are allowed to be blackboxes, and publishers can create their own and distribute them any way they see fit, which effectively lets them determine which browsers may consume their content.
User agent checking (and other fingerprint checking systems), custom plugins which are required, or even going around the browser entirely and requiring a downloadable program or app to playback.
If the standard doesn't have EME, then alternatives will be made which will be much worse. EME is the best possible outcome in a world where DRM exists, and I would be just as happy as everyone else here if DRM was gone entirely, that just isn't going to happen any time soon.
That locks me in to your encryption system, and probably locks me into other things as a result. That also doesn't give me the ability to enforce other DRM things like only one playback per device, or only allowing it to happen between 7am and 7pm, it also means that i need to trust the client, whih is exactly what DRM is trying to not do (because if the publishers could trust the client, an HTML flag for "don't let them save this" would suffice.)
DRM by nature basically needs to be a black box. This just standardized how that black box hooks into the system, and sandboxes it to limit what it can look at (and so we don't have a repeat of the Sony music issues)
The point EFF is making is that its up to the W3C to maintain the balance between the power of publishers and the freedom of users.