At work, a man started wearing a FlatEarthShirt (I wonder how many FlatEarters are at work not advertising their religious convictions). I was not certain whether the bearer wore the shirt ironically or with conviction until someone commented to the bearer that the evidence supports a round Earth. That person got sucked down the rabithole (talking to a FlatEarther is asking for a GishGallop of horseapples).

I suspect that skeptics might have lead to creationists (specifically, biblical literalists) become FlatEarhers by pointing out that the bibles says that the Earth is flat. Rather than giving up biblical literalism, they embraced flat-earthism. They are immune to evidence. To be specific, they use evidence and arguments like a drunk uses a lamppost; for support —— ¡not illumination!