Well, I think you're definitely right about the exposure part, Wesley. I know when I was a child, I wouldn't have gotten into playmobil if it hadn't appealed to something I was already fascinated by. You see, when I was little, I was very into Laura Ingalls Wilder/ Little House on the Prairie. The books, not the TV show. I had every one of the books, and read them over and over again. I also had a little book about what it was like to travel west in a wagon train. So I knew a lot about covered wagons, and my first playmobil was a covered wagon. I was so impressed by the accuracy of it, from the little feed box on the back, to the oil bucket hanging between the back wheels, to the barrel hanging on the side of the wagon to churn butter. If I hadn't already known anything about covered wagons, it wouldn't have impressed me nearly so much.
So yes, I think you are right, a lot of kids just don't know about things in depth enough to be impressed by historical accuracy in any theme. They might see something in a movie or video game, but they aren't reading and learning about it.