Complex is better than complicated
Python has the complex data type built-in and handles complex arithmetic easily.
I worked with several languages before python and most required some hack or additional fudging to do this, and none (other than good old Fortran) did it simply. Now one can always use the extendabiliy of a language to implement complex numbers, but that just generates a raft of different implementations and many incompatibilties. Having it built in keeps is simple, elegant and consistent.
Then add in the bonus of the fantastic libraries such as scipy, numpy etc and it is as they say a ‘no brainer’. Complex numbers are a vital mathematical tool and being able to handle complex arithmetic, solve equations, plot data and many more everyday tasks for an electrical (an no doubt other) engineers is not a luxury; it is essential.