> 10,000s of unemployed cobol developers in the US.

You need to find that Cobol developper, that can work at your office, that will still works for at least the next 10 years, that won't ask a ton of cash because he expect to keep a similar salary as he did before, that is actually competent, etc...

In the other hands, you got 10 000 unemployed java developer that get out of school in less than 500 km around your office, every year, that will do the job nicely for a pretty cheap salary because it's their first job.