[jokteur]

It's because all these jobs using Fortran are scientific research projects. It is not explicitly asked, but if you are doing high performance computing, chances are you will be using Fortran. Scientific codes live for decades.

For example, I'm using a code that has been started in 1981. It is still very relevant and performant. Of course I wish I could use C++ or even Rust, but the fact is that (high performance) numerical computing is first class citizen in Fortran, which is not the case in C++ or Rust. I wish however that the tooling around Fortran wasn't stuck in the nineties.