Wouldn't all Firefox plugins need to be rewritten?
(Plugins need to just go away, and they mostly have.)
Can you explain to me why Firefox would be better off if I didn't have Rikaisama for my Japanese studying or one of a number of Youtube plugins that make the site bearable again by forcing annotations off and 1080p on.
Please share this miracle you speak of.
Edit: eek, looks like it's been removed by the author :( https://addons.mozilla.org/EN-US/firefox/addon/youtube-disab...
Add-ons are brower extensions like the examples you provide.
Plug-ins are Flash, Silverlight, Unity Web Player, and the Java plug-in.
Only the going away of the latter is being called for.
This is most likely an addon, a Firefox extension written in (mostly) JS and XUL. Plugins are the external runtimes embedded in browsers with NSAPI &al: Flash, Java, Silverlight, etc...