History texts are so messed up with modern interpretations. I would hope that novels, movies, TV etc that pass themselves off as based on history do their best to get it right.
Dramatists and historians use different tools. The goals and methods are different. The criteria are different. If you want history then read a history book or watch a documentary.
These race-based dramas are put forth as if they're actual history, and deserve criticism as such. Most of the idiots who go to see this film will come away from it -- just as they did from Oliver Stone's wildly [insanely] ahistorical JFK -- as if they've learned something about history. They haven't.
No one engaging in this kind of historical malpractice deserves a pass on "artistic" grounds.