The basic premise, that it is an anomaly for us to come together into a common social space, is so ridiculous that I have to wonder what her agenda is for making such a blatantly false claim.
People came together from their community to the marketplace to socialize. People came together at church every single Sunday.
You don't get it. The point is that the entire world didn't come together at the same marketplace, or the same church building, or live in the same city for that matter. It's unnatural for humans to all be in the same spot to socialize, we rather split up in groups of manageable size. That's the premise of the author. Now whether that's true or false remains to be seen, but at least understand the point the article is trying to make.