I think people like your father make bank because even though new programmers could learn COBOL, that wouldn't be enough for them to be able to fulfill the same niche your father and other established COBOL programmers occupy; any programming language has a disparity between "the proper way to do things", and the kind of kludges you see in the field, but few have the kind of baggage that COBOL does, in terms of how long it's been around and having things built on top of it.