For what it's worth, there are a lot of good reasons to have access to both (though not saying the article is doing it the best way). There are all sorts of pages that aren't worth the boilerplate and extra time to develop (data-heavy admin pages, trivial about pages, etc). I love SPAs for the heavy-hitting User-facing pages, but for a lot of things they're total overkill and not worth the extra maintenance and development effort