Keeping an open mind to do investigative work first requires that you're QUALIFIED in a field thats relevant to the investigation.
The fact about most conspiracy theorist is that their knowledge on any scientific principle combined wouldn't equal a Associates degree in mechanical engineering.
They critique level headed individuals for their lack of open mindedness but immediately clamp on to any crazy conspiracy and then argue it as truth citing more crazy conspiracy to back up their assertion.
They arm chair engineer the events of the day to make themselves feel more self important, add a context to their empty existence and proclaim a higher status over people who really just have better things to do with their time.
It reminds me of a persone who has maybe been verbally abused, called stupid, picked on and one day decides to gather up enough confidence to start thinking for his self.
But the first idea he siezes upon his the goofiest most absurd concept anyone could imagine but because he's not used to critical thought he goes all in and winds up worse off when he started.