On the contrary, mathematics has formed the basis (no pun intended) of so much software engineering. Take for example the very concept of a function/subroutine/method/ - this comes straight from the world of mathematics (albeit with minor modifications to make it convenient).
The algorithms that do all the heavy lifting in order to facilitate this web browsing experience are all grounded in mathematics - memory management in your kernel, database {everything}, even HTML layout management! The whole of complexity and asymptotic analysis is actually just mathematics.
Many of the pioneers in computer science originated as mathematicians. Alan Turing, John McCarthy and Donald Knuth for example.
It may not seem like it on a daily basis writing CRUD apps in an OO language, but software engineering is inextricably linked to mathematics. Such results are the furthest from surprising!