Given that that's the defense people seem to proclaim every time someone mentions that disabling JavaScript is now buried as an arcane config flag in Firefox.
They say: "just use a plug-in", "just use an add-on"...
What they mean to say is: "just don't disable javascript at all... ever."
Most people, especially those who don't know what a plugin is, should emphatically NOT be disabling javascript wholesale and without exceptions in Firefox. And I disagree that its incredibly hard to google, find NoScript, and follow the directions to install it.
That said, it might be nice to have an optional plugin to easily discover annotations and add your own to pages as you browse.