Well, for a rare change, a number of people are piping up about movies as entertainment, and that is refreshing. Movies are not - and NEVER history (though they might have historical elements) - historical (unless a really old movie as itself being historical) and they certainly are not documentaries.
You want an interpretation of history, read a book or watch a documentary.
Movies are meant to entertain and, hopefully, make a buck (a LOT fail on that point).
The most telling comment of all in this thread, for me, is Dice Rollers "14 year old me" reference. Mass market movies are targeted to a very narrow age range that tops out at around 24. Other ages are incidental to the movie makers and their marketing expertise.
If movies set in historical periods (known as costume dramas in general - aka, the actors wear 'funny' clothes) depended on history buffs and historical miniatures enthusiasts in particular approval, I can give you an exact count of how many more such movies you could expect in the future: ZERO.
Who gives a shit if the movie is exact in detail - go find how much it costs to get say, a real Sherman in a move or get the owner of a perfect structure to agree to let you use their property in a movie (I've done some small scale location scouting, it isn't as easy as you might think), then you will understand why so many compromises are made despite the best of intentions, when those intentions exist - as long as the movie is entertaining in its story.
I'll gladly take the compromises to get costume dramas to the screen. They are amongst the hardest movies to get made because of the built-in extra costs required. So, give the movies a break and just enjoy them as entertainment; that is all they are in the end.