I guess I just don't see the harm. If EME standardization did not take place at W3C, I think it would take place at another standards organization, or privately between content distributors and browser developers. Either way, it still happens and nothing is materially different.
If I go to a site that is "HTML5 Compatible" I should not have to worry if my "HTML5 Browser" has all the proper binary blobs and approvals to support the content.
If something is standard complaint it should work for all platforms that support the standard not just the Billion dollar corporations that paid to get their technology included into the standard
W3C is more to blame that all of them, as they have violated their mission statement with EME and DRM