The biggest danger that I see with the term “based on a true story” is that the true part could only encompass 1% of the plot. We unfortunately live in a culture where a lot of people growing up take their truths from what they see depicted on screen. We can see this in films like Argo’s and its ending act which has Ben Affleck running for his life and slipping past security to board a plane in order to exist Iran. The real truth is that he was able to casually board the plane and fly off with little to no real danger to him.
Consequences of that might be small but once we start to bend the true story to fit any narrative that we see it, we’re left with an extremely skewed view of the world that perhaps too many people might see as factual simply because the movie started with “based on a true story.”