I think Lemmy has a problem with history in general, since most people on here have degrees/training in STEM. I see a lot of inaccurate “pop history” shared on here, and a lack of understanding of historiography/how historians analyze primary sources.
The rejection of Jesus’s historicity seems to be accepting C S Lewis’s argument - that if he existed, he was a “lunatic, liar, or lord,” instead of realizing that there was nothing unusual about a messianic Jewish troublemaker in Judea during the early Roman Empire.
The “evidence” for Atlantis is Plato’s Timaeus and Critias, which is pretty clear in context to be a myth Plato is using to make a philosophical point. He’s not claiming it is historical, and it connects to Plato’s ideal of a “Noble Lie.”