Pseudoscience looks like science but is not. It lacks evidence, method, and testing. It has no shared practices open to criticism and improvement. Wikipedia keeps a list of topics characterized as pseudoscience. Pseudoscience is bad, and I say so plainly.
I rank it by the harm it does when acted on, not by how wrong it is. The worst displaces something that works. AIDS denialism cost South Africa more than 330,000 lives. Cancer patients who chose complementary medicine died at about twice the rate, because more of them refused standard treatment. The World Health Organization counts vaccine hesitancy among ten threats to global health. Astrology is as wrong, and far less harmful.
Some people are more drawn to it than others. In my experience they show little doubt about their own claims, rarely rule out likelier explanations, and stop before a thought reaches its end. They favor beliefs that comfort them and become part of who they are. When science disagrees, the belief wins.
The cure is education and critical thinking: scientific literacy and a culture that values asking questions. But changing one believer’s mind rarely works, so it is seldom worth the effort. When you engage, respect and rapport matter more than facts. The how is in the Discourse Protocol.
Alone, you face an engagement business that profits from false information. That is why I favor pressing governments to regulate it within the First Amendment rather than ban it. Regulation, not ridicule, is the answer that scales.