DRM is malware (I don't seriously believe I have to explain why) - so EME is a malware interface.

I'm completely unfamiliar the entire discussion (I've just ignored it in the past), and I don't actually know why you think that. Could you elaborate?

A EME module is basically a proprietary closed source plugin just like silverlight and flash and shares the same potential security issues.

That's a gross oversimplification: Flash and Silverlight were rich platforms with complexity on the same order as the entire browser. EME has a much narrower interface which provides stream decryption – it doesn't even have the video codec, whereas Flash/Silverlight had complex video, audio, image, PDF, font, etc. implementations with a long history of exploits.

This really matters because so many of those exploits relied on other features to actually run the payload. Not having any of those in the first place is a big attack surface reduction, even if the politics are legitimately debatable.

It makes your computer stop responding to your commands in a bunch of ways.