This seems oversimplistic to say the least. Matlab is used over Fortran as a lot of scientific and numeric work doesn't need to be as fast as Fortran, so having

This seems oversimplistic to say the least. Matlab is used over Fortran as a lot of scientific and numeric work doesn't need to be as fast as Fortran, so having something much easier and faster to develop in with a REPL and data inspector and top tier graphics and GUI building...etc is worth the performance cost as the overall time (including developer) time is much lower in a lot of cases. I've worked with a lot of brilliant academics and national labs folks and they all mostly use Python, Matlab, or Julia for their work. I doubt a single one of them can't learn Fortran. Indeed, some use it when needed on super computers after they've built a prototype in Matlab. Remember, there was a time when scientists thought anyone who needed to use Fortran over Assembly or Assembly over manually configuring the computer were just too dumb/spoiled. Tldr: Fortran, C/C++, Matlab, Python, Julia are all great and serve different roles with pros and cons.