Loops in Python are excruciatingly slow, for no reason. Some algorithms are naturally written using loops, and Python makes this very uncomfortable, forcing you to rewrite your algorithm in a non-natural way. I hate writing numerical code in Python due to that; it just feels uncomfortable.
For scientific computation I just need multi-dimensional arrays of floats and fast loops. Fortran has both of these things natively. Python has neither.
I prefer vector types for this kind of stuff, as they are more compact than loops and naturally lend themselves to auto-vectorisation. In the end it comes down to the programming style preference.
A lot of the code used in scientific computing cannot be vectorized because the latter loop is dependent on the former loop (like time stepping in a simulation). It’s not really a programming style preference.
For scientific computation I just need multi-dimensional arrays of floats and fast loops. Fortran has both of these things natively. Python has neither.