As far as who is responsible for the spread and wide acceptance of Calculus, it was Leibnitz and the Bernoullis who deserve all the credit.
After Newton, Calculus was dead in England for another ninety years, in part due to Leibnitz-Newton controversy and also due to the needling of Bishop Berekley at the shaky underpinnings of the subject making the English eschew analysis in favor of classic geometry. Math major here. :)
How interesting. Could it also be the English versus German bias as well?
Back then it was nationalism and personal pride (it's said Newton himself wrote the report convincting Leibnitz of plaigirism!) played a role. I have no idea whether such a thing had anything to due with this latest "Einstein versus Newton" and I'm no authority on the subject - but you'd think they'd at least make a mention of it! Math history, suprisingly to some, is a such great subject - full of interesting characters and controversites all around the development of the beautiful ideas of mathematics.