While I agree that semantic HTML is a nice thing, I am also confused because the HTML I saw in 1999 didn't look like what the author suggests. If I am not completely mistaken, nav is an HTML5 element that didn't even exist back then.

Instead, we used tables inside tables insides tables inside iframes to structure our navigations. CSS was still some mystic magic that only a few wizards knew how to use effectively. And in many cases, the result was actually less semantic than what we see nowadays.

So the arguments seem a bit odd, although I support the spirit of the message.