Some sites just wouldn't work well with HTML+optional JS. Google maps (IMHO) would not work well that way, so using an offline-oriented model would make better sense.
That being said, if your a news site, or a blog, yeah, a simple static page is probably a better solution.
The article is older but the advice is sound: only reach out to the server when you need to and ensure your client-side state doesn't break when you can't.
It's a little strange that they avoided naming any JS MV* frameworks even though some where out by then -- Backbone, Knockout, Ember, Angular, if I recall. But this article makes the point that all future JS MV* development went on to consider best practice in the years to follow.
- only slightly sarcastic.