The "weekend hack" that was Python, a philosophy carried into 2.x, made it a supremely pragmatic language, which the data scientists love. They want to think algorithms and maths. The language must not get in the way.
R wants to get things done, and is vectors first. Vectors are what big data typically is all about (if not matrices and tensors). It's an order of magnitude higher dimensionality in the default, canonical data structure. Applies and indexing in R, vector-wise, feels natural. Numpy makes a good effort, but must still operate in a scalar/OO world of its host language, and inconsistencies inevitably creep in, even in Pandas.
As a final point, I'll suggest that R is much closer to the vectorised future, and that even if it is tragically slow, it will train your mind in the first steps towards "thinking parallel".