Yeah, it's true that lot of the sites still using Java hasn't been updated with the correct instructions about how to enable it in FF 24 yet - and they should fix that as soon as possible of course.
Still, it's a much easier thing for normal users to figure out than how to update Java (which they must do quite regularly to get Java to run at all).
I did a little Googling and it turns out that Java still runs in Chrome on Windows, it's just banned on OS X.