Is this a joke? Ask any mobile or desktop app developer (people who program UIs in a non-broken platform) how they think about having state inside the views.
Only on the web there exist people who hack around for so long they actually believe the hack is the right way.
His point, stated with a bit too much ad hominem, is that with such a serialization you can scaffold entire dynamic web apps which can include form submission where the form dynamically updates based on rules & current state, uses a configurable method, and more, whereas DOM is inherently a "view" and has no concept of state
I mean, you don't see any value in being able to declaratively state an entire app? ...