I mean they sit on a board responsible which is taking years to make Javascript a tractable language, and at this rate it looks like that is never going to happen.

Shumway has everything to do with EME not on a technical level, but on a business level because a superior Flash replacement games developers and other content providers found more dependable than the original Flash would put them in a stronger bargaining position vis-a-vis the other majors.

Good technical execution is Mozilla's strongest bargaining chip and if they fail at that they make themselves less relevant.