Typical "follow, not lead" mentality from Mozilla. Anybody who remembers the very early days of the project, back when releases were named M1, M2 and so on, will remember the many fights over various aspects of the browser that ended with "We must do this because Internet Explorer does it" or "We can't do that because Internet Explorer doesn't do that."

Now, in 2015, it's more of the same, following Google Chrome instead of having a vision, sticking to it, and just implementing it.

Plugins are a source of performance problems, crashes, and security incidents for Web users.

They're also a source of cutting-edge and/or specialized functionality that isn't part of the browser and may never be.

Websites and publishers which currently use plugins such as Silverlight or Java should accelerate their transition to Web technologies

I'm having a hard time coming up with a definition of "web technology" that doesn't include Java, outside of "things that are baked into the browser out the box" which is awfully narrow.

The Web platform is powerful and can usually do everything that a plugin can do. In the rare cases where a site needs to extend Web technologies, the recommended solution is to develop the additional features as a Firefox add-on.

Why should it be rare? Innovation will always outrace the ability (or willingness) of browser vendors to incorporate new technologies. I mean, there's a reason plugins exist and I don't see that anything has changed to negate that. They're a place to try out new stuff, or things that aren't widely used enough (or supported by a company with enough money) to get incorporated into the browsers.

OTOH, maybe this is a win. We need to get away from this whole "The browser is a poor man's operating system" model anyway. Let the browser do a great job of browsing hypermedia and then hand off to specialized programs when we want to do something outside that paradigm. In this regard, JWS is a great approach that should probably be more widely used.