You can couple this with the fact that COBOL and mainframe systems are taught at an alarmingly small number of universities in the US. The need is there, and the pool of young, skilled professionals is *severely* lacking.
It might not be cutting edge, but it's comfortable living.
jfruh writes: "Here's an old computer science joke: What's the difference between hardware and software? If you use hardware long enough, it breaks. If you use software long enough, it works. The truth behind that is the reason that so much decades-old COBOL code is out there still driving crucial applications and banks and other huge companies. Many attempts to replace COBOL applications flopped in the 1980s and '90s, and we're stuck with them for the foreseeable future — but the Baby Boomers who wrote all that code are now retiring en masse. So if you want a successful IT career, you should probably learn COBOL."