Earlier quoted context omitted.
If you're going to pick nits at least use the full definition. For a shorthand it was accurate enough, and in popular usage the assumption is not that it is incorrect but that the facts as known do not support the outrageous claims made by the believers in these theories. https://en.wikipedia.org/wiki/Conspiracy_theory#Etymology_an... Examples such as the Climate Change hoax, Moon Landing hoax, COVID-19 hoax, New Wor…
The problem is that the term is a combination of name calling and appeal to authority used to quickly discredit a theory, and has been applied to significant minority theories that have turned out to be true. It’s more work but better form to avoid the term and confront fringe theories with solid argumentation.
If fringe theories would be susceptible to reason then the bulk of them wouldn't exist and the remainder would not be classified as a belief system but just another theory waiting for confirmation or rebuttal.