It's not unheard of. But you must understand that these are people that have a pretty decent job security in an often huge codebase that has been aquiring cruft for 30 years in language most people don't understand. I would like to be able to claim that the code is good, but some of the people writing it in the first place were not programmers. It is not strictly bad, but some parts are just mine fields.

A bit related:

I spent 2 years of my life on a C codebase written by mathematicians that would much rather have written it in APL. I don't know if you have seen C written as APL, but that is 2 years of my life I will never get back. I left for a lesser paid, more fun job. Upon leaving the manager offered me a 60% pay raise (yup, I should have had higher demands, but at least I proved myself :) ).

Unless you enjoy torturing yourself, legacy COBOL programming is not very rewaeding, and at least in Sweden, most of it is slowly being moved to other languages.