I believe this is due to historical reasons, in particular due to the Bourbaki and the French school of mathematics where abstraction was heavily prized. On the contrary mathematics in the Soviet Union had more of a focus on intuition and geometric grounding for mathematics, however history played its course and mathematics is taught more towards the Bourbaki style these days, however it did bring out gems like [1] which give an opposite, albeit extreme, view of how mathematics should be taught.

[1]: https://www.uni-muenster.de/Physik.TP/~munsteg/arnold.html