Any compiled language will be drastically faster than an interpretive scripting language like Python (although numpy/scipy is generally C or Fortran libraries compiled to be called by Python). Having said that I used Fortran for my PhD to do radiation simulations because I was implementing a new methodology into existing code.
In my opinion Fortran is easier and safer to use for scientists with little background in coding because it was built to do math/simulations really well AND it's readable almost like psuedocode (compared with C or C++). Also, modern Fortran is object-oriented which makes building reusable tools and large packages pretty easy.
Having said all of this I think a lot of the physics/nuclear/aerospace/finance community is probably transitioning into more modern languages and starting to employ people with actual CS backgrounds to build with more updated coding practices.
In my opinion Fortran is easier and safer to use for scientists with little background in coding because it was built to do math/simulations really well AND it's readable almost like psuedocode (compared with C or C++). Also, modern Fortran is object-oriented which makes building reusable tools and large packages pretty easy.
Having said all of this I think a lot of the physics/nuclear/aerospace/finance community is probably transitioning into more modern languages and starting to employ people with actual CS backgrounds to build with more updated coding practices.