As someone who maintains a large Fortran codebase actively maintained from the 50s, I can say with 100% confidence that syntax, compiler, and other tools aren't even 10% of getting up to speed. It's some of the worst code you will ever see. A lot of it predates "GOTO considered harmful." It also comes from an era where different common blocks and subroutines were moved into and out of memory using a custom virtual memory system.

The demand for Fortran/Cobol experience has nothing to do with training. We need to make sure you are masochistic enough to trudge through the sludge.