Sometimes the more you know, the more possibilities could be out there. We are not in a 100% transparent world. A single signal could mean a lot that one is not able to see. So based on some signals we could observe, there come related explanations. We could label a category with different tags. Conspiracy theory is one of them. Though I do believe that conspiracy theories weigh people's motivations more, which is not quite fit to most of mainstream perspectives. Hopefully, I won't get downvoted too much with this comment;p
Yeah, I think you are kind of circling around a central issue. Some evidence emerges of something untoward happening and the conspiracy nuts jump on it. There ends up being a lot of noise on top of a little bit of signal. People who fancy themselves rational dismiss it while the nuts keep amplifying it. Then much later more/most of the story comes out and sometimes it's a lot worse than the nut jobs even speculated.
[edit] typo