For centuries, it hasn't been uncommon for retiring generals to write about the campaigns they fought in. Their works ranged from highly accurate recordings of history to blatant self promotional works of fiction. Why did people read these? As much for entertainment as anything else I presume.
The interesting thing, for me, is that these works always come under the microscope at some stage by historians, journalists or just ordinary people trying to uncover the truth behind certain events. The fiction gets tested and doesn't stack up. We may not always agree on the causes, the right or wrong, etc (which makes history so interesting) but we are not too bad at getting the actual events accurate.
For my mind, if it takes a movie with a liberal dose of fiction to get people interested in discovering more about history - so be it.