The discussion revolves around the criteria for what constitutes "crackpottery" on the Physics Forums (PF) and whether historical figures like Copernicus or Einstein would be banned for their non-mainstream theories. It is emphasized that personal theories are not inherently crackpot but must adhere to PF rules, which prioritize discussions based on peer-reviewed literature. The distinction is made that crackpottery often involves a lack of evidence, logical fallacies, and ideological biases, rather than simply being non-conformist. The forum does not accept personal theories unless they are published in reputable journals, and even then, the quality of the theory and the user's reputation play significant roles in determining acceptance. Overall, PF aims to maintain a standard of scientific discourse that excludes unfounded claims and pseudoscience.