Besides the slight hypocrisy, I understand the point the author is trying to get off as simplify simplify simplify. When you have been doing it for as long as he has, seems like the natural progression.
That's not actually the point. The point is that the author wants to be seen as a badass iconoclast. Unfortunately, he (or she) has no actual valid ideas, so he's joined a cargo cult of simplicity-worship, as if eschewing everything complex in a web design automatically makes it good.
The points made are hilariously ignorant. The argument about how it was dumb of people to make Doom for DOS because "DOS wasn't designed for that" is jaw-dropping. Claiming that you should write all web stuff in C, OMG. The defensive explanation about why they build sites with Flash. Oh wait, I just figured it out. These guys are Flash developers and nobody wants Flash these days, so they're flailing, trying to explain why modern web development practices are no good, but sites that consist solely of a Flash widget are totally where it's at. All is clear now.
I think the author of the article wants to compare that to, say, the starcraft menu interface. Or windows desktop applications. Or, to a lesser extent, flash interfaces. This would be a good example. Can you imagine doing this in HTML ? http://demo.northkingdom.com/gettheglass/
And he does have a point. Recreating the starcraft interface in HTML5+CSS+Javascript is possible of course. In the same sense that you can write windows 95 in pure lambda calculus (frankly, I think the lambda calculus rewrite would be easier since there's translation tools).
I'm with the rest of the people here. Those fancy interfaces have little function, don't interact well with the rest of the world (e.g. search engines, content aggregators, ...), they're accessibility nightmares, ... But they're cool. But my opinion on them has exceptions : for some things, like games, that's more important than all those other things.
You are making the exact same mistake he is. You are picturing what you remember of YouTube and in your recollection, it is simple. This is because they have done a reasonable job of using a simple design, not because they have avoided "moving" things. Go look and you will find plenty of menus, tabs, comments, and other ui elements that are built of the exact stuff he says is worthless. Holding any of these sites up as an example of being essentially just text and a few images just indicates that you don't have much of an eye for detail.