JFK and Reason

I seen a recent poll that concerned me it said that 78% of Americans still believe in a conspiracy with regards to the death of JFK. Anyone who wants to know the truth knows that Oswald did in fact act alone. They know that Ruby was not sent by the Mafia the facts are there if anyone wants to know the truth. The "magic Bullet" Is not magic at all when you see where the people in the car were actually sitting. I used to belive in the conspiracy theory that is until I really started to read and reseach the whole thing. I am from Dallas so I know how many people make money from the conspiracy. Every single day they are people at dealey selling books, videos and lies to gullible people who are not really interested in the truth but rather the story. Why do you think Americans tend to be so gullible?