Earlier quoted context omitted.
Spherical Earth, on the other hand... I have not found an explanation for that epiphenomenon, although I have concluded that it is not meant ironically.
Some of that is a put on, trolling people over something obviously silly. And some is real.
I think the whole Flat Earth thing is like the "Kubrick filmed the Apollo 11 landing on a soundstage" idea... it started out as a joke, and then got out of hand.
That seems to be happening a lot lately.