> A conspiracy theory is a belief there should be a conspiracy but without the necessary qualified evidence.
That is an arbitrarily high standard. Just because the subject of a hypothesis is that there is a conspiracy doesn't automatically make lack of evidence problematic. Even for natural phenomena there can go decades before a hypothesis is backed with evidence if ever (e.g. Einstein), human interactions and particularly intent is much more unlikely to leave a trail of evidence so I don't get how being even more strict with it helps with our knowledge gathering process. All conspiracies that turned out to be true were conspiracy hypotheses before they were proven and this defense could have been (and was, and is) used to stifle the process of evidence gathering.
This doesn't mean most of the conspiracy hypotheses aren't far fetched, emotional and poorly argued, nor that all is entitled to public attention equally, but we can't apply different epistemological standards between conspiracies or natural phenomena (science) when we are faced with unknowns.
> Given the terms I find it’s not at all far fetched to conclude there exists some common mental health defect
If we judged this premise by the standard you've posited, it would be equally problematic. In fact, we know in the past, states have abused psychiatry to discredit dissenters. Check out Soviet Union and their "creative" diagnostic labels used against political dissenters as an example.