Neurotypicals mutually accepting apparently contradicting thoughts

[Suzette]

Galileo, Copernicus and Cantor went against established beliefs and were never considered crackpots. If unpopularity of their views is not a reason to dismiss them, how come crackpots are treated as of unpopularity of their hypothesis is a reason to dismiss them?

You are making broad assumptions about what other people thought about these men hundreds of years ago.

From etymonline.com
""mentally unbalanced person," 1898, probably from crack (v.) + pot (n.1) in a slang sense of "head." Compare crack-brain "crazy fellow" (late 16c.). Earlier it was used in a slang sense "a small-time big-shot" (1883), and by medical doctors in reference to a "metallic chinking sometimes heard when percussion is made over a cavity which communicates with a bronchus."

I quoted that eymology to demonstrate how the meanings of words and phrases change over time. While "crackpot" was not used to descibe these men their theories were not widely accepted and many did in fact believe they were crazy.

So, why do some peoples ideas get dismissed as "crackpot"?

This question is not a problem but the question it's self has made an assumption that others opinions matter. Opinions do not mattter. Only facts and evidence matter. In the case of the ideas of these historical figures, time has given sufficient evidence to know that their ideas were true.

Someone shouting about "the end is coming" can not be proven to be true so many will form the OPINION that this person is carzy. Time will provide the evidence to confirm that the end had come or not.

 

[Myrtonos]

"Galileo, Copernicus and Cantor went against established beliefs and were never considered crackpots."

Upon what basis do you make that statement?

So if you take Galileo and Copernicus, they were accused of heresy, not pseudoscience, and by people like the pope who could not conceive that any crucial secret about the world could be left out of the entire western tradition of knowledge, let alone all traditions of knowledge at the time.
Thus the pope and many others at the time did not accept the falsifiability of an established tradition, something anyone who understand physics would accept.

While the theory of continental drift may have been dismissed, it was not on par with the conspiracy theory of hollow earth. Also, while the idea of antiseptics may have condemned by the establishment of the time, it was not on par with the conspiracy theory that Luvox is a treatment for COVID-19.