Well, you do have a point in that COBOL jobs are safe places where you don't have a lot of need in staying up to date with the freshest tech, leaving more time for other things in live than code, same as it goes for many JavaEE shops.
However, lots of banks are rewriting their COBOL code in Java, so you might end up writing some Java anyway.
However, lots of banks are rewriting their COBOL code in Java, so you might end up writing some Java anyway.