I think his point is that it's a communication system that facilitates communication amongst
everyone. And
everyone can communicate in words, typed out[0]. And not everyone can produce or effectively communicate using beautiful video, high quality graphics and, I guess, responsive design. [1]
It's interesting to wonder what the next-common "wide area" communication mode is -- photos are widely shared, but is there a lot truly communicated with them? I guess it depends on whether you think those picture's typically say more than a thousand words. Videos, too. They serve as a topic of discussion amongst peers, not as a mode of discussion themselves.
In fact the deeper point remains even if I conceded your argument: there are always those who excel in the creation of art and in presentation, regardless of medium. What makes the Internet different is that it facilitates peer to peer communication, that quality powered for the most part by the universality of written text. I guess that's why it if often compared to the invention of the printing press, another time such a fundamental shift in human communication took place (facilitating many to everyone, but not everyone to everyone).
Those who excel in arts and communication -- and, to an unusual degree! engineering -- are still the magic wizards/grey eminences of the medium, prominently shaping something that wouldn't exist without them.
[0] Words, typed out: A manner that's arguably truly more efficient and useful than what it's originated to represent, speech. Imagine consuming all the text content you read everyday on the web (such as this!) delivered by speech.
[1] Leaving out the fact, that of course, not everyone has the ability to participate in words, typed out. While I do think it has served to interconnect everyone in terms of exchanging thoughts, it also serves as a means of separation between those who can and those who can't: lacking access or straight up capability to use this mode.
Edit: added some more thoughts.