The best explanation I've heard regarding why people come up with CT is our inability to accept how random violence can be, and how vulnerable we are to it, every last one of us regardless of position. In a free society we are subject to these random acts and that's just the price we pay. Much as we do, we cannot prevent a determined person(s) from committing these acts, especially when those people don't care if they're caught and/or die in the process. This has been true from Oswald to 9/11, and beyond. Those that look for the truth will find the truth, but if it doesn't fit their personal agenda, well then, they just make shit up, using whatever elements of the real truth that fits their story. With the advent of the internet this has grown exponentially. I fully expect our society to collapse should we not be able to get a handle on this. There are now generations of people that get all, ALL, of their "facts" from the net and even more sadly, movies, where "dramatic license" trumps the real events. We can only expect more to come.