Conspiracy:
An agreement to perform together an illegal, wrongful, or subversive act.
Insofar as 2 or more people have coordinated, colluded, or planned an illegal, wrongful, or subversive act, a conspiracy is afoot.
In fact, almost all significant illegal, wrongful, or subversive acts include conspiracies to commit said acts.
I think it is safe to say that the present sociopolitical and socioeconomic landscapes are rife with activities, writ large, that are, from some reasonable perspective, illegal, wrongful, or subversive in nature.
To remove the idea of conspiracy as a valid concept wielded by reasonable people is perhaps the most surgical of injuries to society which might otherwise seek to prevent or interfere with these kinds of illegal, wrongful, or subversive acts.
When a couple of people decide to rob a liquor store, we call it a conspiracy. When someone suspects that a global cabal of banks might be colluding to screw the world over, we discredit them as a “conspiracy theorist”. (Libor)
Insofar as it is reasonable to suspect that an individual might be capable of doing something illegal, wrongful, or subversive, it is also reasonable to suspect that an organisation might might do the same.
We are conditioned to protect the systems and individuals that parasitise society, because we do not wish to confront the flaws in the system we serve.
That said, there are plenty of nutjobs out there with outrageous claims. Some of them are delusional, some of them are attention seekers, some of them are merely ignorant or misinformed. But we should call them nutjobs, not conspiracy theorists.
We ignore our civic duty to be vigilant “conspiracy theorists” at our peril. In doing so, we give cover to the lies that are big enough to be easy to believe.