Because it works. Every part needed to run those machines, even line of code, every possible cause of failure is well documented and there are layers and layers of redundant protocol to ensure that if something does go wrong downtime is minimal.
The entire purpose of these machines are designed to run for as long as they’re needed. They’re not replaced or upgraded because they were never meant to be. A lot of effort went into this being the case.
Because it can do something that the alternatives can’t do or because they refuse to use something more modern?
Because it works. Every part needed to run those machines, even line of code, every possible cause of failure is well documented and there are layers and layers of redundant protocol to ensure that if something does go wrong downtime is minimal.
The entire purpose of these machines are designed to run for as long as they’re needed. They’re not replaced or upgraded because they were never meant to be. A lot of effort went into this being the case.
“It can’t be hacked”
Of course, it can, and a lot more easily than a TLS stream, but try convincing them of that. So, more like they refuse to use something more modern.