Earlier quoted context omitted.
Has the general notion of "conspiracy theory" ever carried any positive value? It only seems to exist to discredit "doubters against the majority consensus" without substance. But I guess words like "crank" wouldn't even exist if there weren't many people like it, so it carries some "definitional" value. Because they show total disregard for someones opinion (in a more formal way: "unlike you/them, i completely agree…
Our notion of "crank"/conspiracy theory is a logical consequence of "extraordinary claims require extraordinary evidence." When that evidence isn't provided all that remains is an exceptionally convoluted explanation, generally involving more parties than necessary, hence "conspiracy."
On the other hand, discussing statements without evidence (even if they are not presented as beliefs), has some (opportunity?) cost, which the "theorists" are willing to pay