Physics Forums prohibits speculative posting to maintain the quality and credibility of discussions, focusing on established scientific principles rather than unsupported theories. This policy is intended to prevent the dilution of valuable scientific discourse, as past experiences showed that allowing speculation led to a decline in the site's overall quality and engagement from knowledgeable members. The forum aims to serve as a resource for learning and understanding existing science, rather than a platform for developing new or speculative ideas. While some argue for a space for such discussions, the consensus is that it detracts from the educational mission of the forum. Ultimately, the site prioritizes credible science and encourages users to seek out other platforms for speculative discussions.