Back in the 60s after John F Kennedy was murdered, there were two broad schools of thought; that he had been murdered by a man acting alone (no conspiring) or he was murdered by a man[men] acting in coordination with others (conspiring.) Thus in this case you had people who believed the official narrative, and everybody else, who had theories "about conspiracies." This particular case seems to have been strong enough to effectively redefine the term "conspiracy" to mean any theory contrary to the official narrative.
The problem is that in other cases, such as 9/11, the official narrative is a theory about a conspiracy. As are all of the alternative theories. In the case of something like 9/11, literally everybody agrees the numerous perpetrators conspired with each other; the disagreement arises over who exactly those conspirators were. In the 'proper' sense of the term "conspiracy theory", everybody believes at least some conspiracy theories. But in this new modern sense of the term, "conspiracy theory" applies to only to those who contradict the officially endorsed explanation of events.
(Incidentally in the specific case of JFK, only a minority of Americans believe the official one-man narrative: https://fivethirtyeight.com/features/the-one-thing-in-politi... Was it the mafia, the CIA, the Russians? Somebody else? Who fucking knows. But most people don't believe Oswald acted alone.)
The problem is trust, and many of the world's governments and corporations (I would probably argue most) have proven to be unworthy of the public trust.
Really sad bonus thought: If you see what happened in the aftermath of 9-11, and look at how much money is made from warfare - how much of a stretch do you think it is for an otherwise typical person to believe it's an inside job?
This is why I don't watch the news anymore.
The people with the most accurate view of reality lie somewhere in the middle and do the critical thinking for themselves. The reality is that conspiracies do and always have existed, and the mainstream today is very different than the mainstream 100 years ago, which was different 100 years prior, etc. (because those mainstreams were proven wrong on many levels, as our current one will be).
Ask yourself honestly: would you have been on the side of the Catholic Church in the Galileo inquisition, had you lived in that time with your personality?
On the other side, would you have been a patron of the charlatan John Taylor had you lived in his time? https://en.wikipedia.org/wiki/John_Taylor_(oculist)