I'm not a mathematician of physicist, but I suspect that these disciplines are ahistorical largely out of necessity. They now require the grasp of so much technical material that there simply isn't time to teach the history of the discipline. I see no reason to think that this is a particularly good thing.
Somehow you are implying that philosophy is so simple all the material can be covered, so there is time to study the history?
What's important is understanding. If studying the history aids understanding it might be worth the time.
I believe studying the history in physics impedes understanding, because it builds up mistaken ideas that become hard to tear down.
For philosophy I'm not sure but I suspect it's better to order learning so as to make a logical progression and that isn't the same as the historical order.
I didn't mean it as a dig at philosophy for being simple. But I think it's true that there is less "essential technical material" to cover in philosophy. There's no equivalent to spending 3 months practicing solving differential equations.
>I believe studying the history in physics impedes understanding, because it builds up mistaken ideas that become hard to tear down.
This can be true in some cases of course, but there are also good ideas that get forgotten about or become unfashionable. And without studying the history of the discipline, you will often end up rejecting straw man versions of historical ideas rather than the ideas themselves.