Erm, because that's the impression I've got from the tutorials and demos. I guess a "Add $Framework to a bit of your app" isnt' sexy: the ones I've seen add their own routing and focus on SPAs. Rather than "Here's some incredibly complicated information to display, and we need to be fairly interactive over it (and how other data on the page affects it)".

Would it work if you didn't have a vanilla JS application but a traditional web app?