Ok, now I see where the confusion is coming from. Fortran is used pretty much exclusively for numerical software. A lot of numerical software has very simple control flow using very few and very simple types. Numbers haven't changed much since they were invented. Fortran is used very differently than you're imagining.

...by people who have a reason to look at it.

What is it about Fortran’s control flow that makes you think it’s particularly hard to read? Say, harder than Python? Note that people don’t generally use computed GOTOs any more.