Besides, it is a paraphrase of a well-known George Carlin quote.
Because like he said, the average person is not so smart, I guess including themselves haha.
Average people fall for bullshit all the time when the charismatic bullshit artist is able to spin the setting, facts, and narrative.
The rules around a criminal trial are designed in such a way to give prosecutors plenty of opportunity to shut that down. And prosecutors are very, very experienced at playing in that arena - far moreso than even a serial bullshitter is.
Also, there's a lot of selection bias that goes into being a victim of fraud. It's true that some kind of fraud will work on just about anybody, but no particular kind of fraud is guaranteed to work on a particular person. Jury selection is semi-random, it's not pulled from the pool of people who respond affirmatively to Nigerian Prince spam-emails.
How could anyone believe this? “Average” people fall for bullshit all the time.