Not separating the state from the DOM (more than necessary, that is - at the client/server boundary) makes a bunch of things much easier. You can just manipulat

Not separating the state from the DOM (more than necessary, that is - at the client/server boundary) makes a bunch of things much easier. You can just manipulate the DOM and the state stays with the DOM, so there's nothing to sync internally within the JS app. You only serialize from DOM and to DOM at the server API boundary. No need for the "rendering" in response to state changes. You just change the DOM intuitively, and that's that. And that makes "vanilla" browser apps easier to write too.