There's no question that you can make a good living learning to program dinosaur machines in COBOL, but then you would have to spend your life programming in COBOL.
Good coders want to use the best tools, because using good tools are part of being a good programmer. Unless things have changed radically, those tools don't exist on mainframes -- or at least, what most people consider the best tools don't.
Taking one of these jobs is more or less the exact opposite of starting your own company.
Some corporations made hefty investments in big iron. That doesn't make them economically viable today. I still believe that performance, energy conservation, space utilization, HVAC optimization, etc., etc. are reasons for updating to the latest hardware and the operating systems that they run. From a strictly hardware standpoint, the old stuff gets hairy to manage and maintain.
You can keep driving that 1979 AMC Matador, and you can keep rebuilding the engine, and patching the rust holes. But after you've spent thousands on the upkeep, you could have bought a new car that gets better gas mileage and won't strand you on the freeway half-way to work on a rainy morning. Any corporation that didn't look to the future, is the corporation where you'll find the dinosaurs. And that doesn't say much for corporations like State Farm.
Mainframes still do a lot of heavy lifting. Like processing the world's credit card transactions in real-time.
VisaNet is four strategically-located mainframe supercenters for financial transaction processing. 3000 transactions/second. 50 million LOC. Uptime and five-second-transaction time crucial.
I disagree. Factoring support, downtime, and hardware I think a mainframe will in an appropriate domain be just as cost effective as a cluster of small servers.
Mainframes are the best system for a lot of jobs and problem domains and dismissing them because they are "old school" is silly at best.
To put it in car terms. If you are moving papers it doesn't matter if you have one large truck that can carry 1 million papers or 1 million small cars than can only carry 1 paper.
But when you want to move a space ship it's better to have 1 big truck that can carry it at once instead of having to disassemble it fit it into your cars then reassemble it at the other end.
I would like to learn how to use a mainframe? does anyone know if any of the mainframe os's (z/os and os/400 off the top of my head) can be run in a virtual environment? so I can learn them?
Good coders want to use the best tools, because using good tools are part of being a good programmer. Unless things have changed radically, those tools don't exist on mainframes -- or at least, what most people consider the best tools don't.
Taking one of these jobs is more or less the exact opposite of starting your own company.