I think it's the idea that math and science are the same regardless of their history. You can learn the history of them, but the answers don't change when you do. On the other hand, your answers about historic and cultural questions can change drastically depending on how informed you are.

Also, the level of rote memorization required vs. logic and analytic thinking. You think math and science could be improved via learning their history; I think history and culture can be improved by learning more about the reasoning behind individual things. Less focus on when and what and where; more focus on why and causes.