I don't disagree with you in any way :-) these are web apps, not just plain websites with something like a commenting system.
Even with these web apps, I think its best to explain why JavaScript is needed. Except for google analytics, I'm still a huge fan of Unobtrusive JavaScript, if only because it makes for cleaner site organisation and code separation.
Really? Etherpad, Google Wave, Google Docs. Every HTML5 game I've ever seen. Aviary, Picnik, Picozu. etc.
I generally agree with the point that most sites that present text to a screen don't absolutely NEED JS to work, but there are a myriad of apps out there that do.