While I disagree with the authors completely, comparing GPT-3 to a working plane is also wrong.
GPT-3 can produce human-sounding pieces of text that don't have any meaning. I am quite certain that it will prove a dead end in the advancement of NLP, simply because trying to learn human writing by matching lots of text is unlikely to create an accurate model of the world that you could use to produce meaningful communication.
Well, the first flight at kitty-hawk was an unimpressive 12 seconds, so it still took a quite a while for people to actually start admitting that practical powered flight was possible or useful.
Analogously, GPT-3 is clearly far from perfect. But it does seem to be sufficiently useful for people to use it as a creative writing tool already today.
(Tantalizingly, there's some signs in people's playing with it that seem to suggest the beginnings of a there there. However, like a lot of people, I've been disappointed too often before to be sure; not without a lot more research. So I won't push that point today. )
It's a kind of bitter-sweet irony.