I'd argue two points here: Recruiting and technical debt.
There may be challenges getting the talent you want with legacy systems and I believe you're building a technical debt as you'll hit a wall with your infrastructure and have to upgrade/migrate one day anyway.
The top comments on this posting are ex-employees talking about how they've been migrating many (most?) parts of the system to C++, so yeah, even Bloomberg management agrees staying on FORTRAN is probably a bad idea.
There may be challenges getting the talent you want with legacy systems and I believe you're building a technical debt as you'll hit a wall with your infrastructure and have to upgrade/migrate one day anyway.
The top comments on this posting are ex-employees talking about how they've been migrating many (most?) parts of the system to C++, so yeah, even Bloomberg management agrees staying on FORTRAN is probably a bad idea.