>On top of that they tend to be stodgy old corporate companies that developers hate, where you have to wear a suit to work and being seated by 9AM is more important than doing your job well.
That I can attest happens, less so today but then such places lost most of their talent as those that could and able to move on did and those that didn't, well they would of been close to retiring and with that. Hence technical debt increases. But it's not just knowing the COBOL, it's not just knowing that business logic, but how the two go together - THAT level of knowledge was always undervalued in many institutions alas.
The language itself and some of the tooling might be quaint, but I feel that sometimes it's also much simpler than the replacements from turn of the century. Not all corps are stodgy ones, but that's usually contractors that have few COBOL experts, sometimes just to check over work of other contractors. Some vendors are worse than others, some better.
On top of that they tend to be stodgy old corporate companies that developers hate, where you have to wear a suit to work and being seated by 9AM is more important than doing your job well. Then there's the fact that it could be career suicide to spend so long on tech that fewer and fewer companies are using. And you'll need an exit plan because it's used at become companies that do regular mass layoffs, they've probably fired more cobol programmers than they'll ever need. They should be paying a hefty premium to get people.
The language itself and surrounding systems can't be any worse than the standard enterprise XML DSL rubbish can it?