Later in the post he elaborates on this. I think he's more opposed to the pure text aspect of it.
I guess you and I have different use cases and definition of "modern application usage". I assume you spend most of your day in a GUI, while I spend most of mine in a terminal.
Pipes can handle binary data and sure you could pipe Skypes output through sed or awk... Though something like ffmpeg is more likely, and it will happily take stdin as input.