If it's not like the movies
That's how it should be
Not Like the Movies, Katy Perry
Fiction can have a profound effect on people. Stories aren't just idle amusement - they cause emotional and physiological responses. The brain can't tell fact from fiction. This is empirically observable - people cry at movies, or feel heartwarmed by books.
Fiction can also distort your memory of real events that you experienced. The film Dog Day Afternoon is based off of a true attempted bank robbery. One of the real bank robbers, John Wojtowicz (portrayed by Pacino), saw the movie after it came out. The short film The Third Memory shows that his memory has been altered by the fiction. He can't help but pantomime things from the film, and he has a manufactured memory about Nixon's role on the robbery.
Movies retcon things all the time, which can exploit this property of human psychology. Did the Chappaquiddick incident match what happened in the film Chappaquiddick? I wasn't alive, but I can't think of the event without thinking of the film. The line gets blurrier for fiction that is sort of based off of real events (whether explicitly or implicitly).
Popular fiction unfortunately creates circumstances where there are objectively good and bad characters. Harry Potter's good, Voldemort is bad, and "The Dark Side" is self explanatory. This also happens for "historical retellings", painting characters as good or bad. Most people and situations in real life are in the gray. There are not often objective "good" and "bad" sides to a conflict.
I'm not against fiction - I have reviewed many fictional movies on this site - but I am against emotional and manipulative fiction. For movies, I prefer lighthearted ones limited emotional impact rather than fake retellings (or half-retellings) of real events meant to emotionally manipulate me.