COBOL is like bedbugs. Nobody likes COBOL; the reason it sticks around is because it's damn near impossible to get rid of.

The reason it sticks around is because lots of enterprises either have mission critical code that works well in it and still has the same requirements (leaving no reason to replace it) -- or because poorly documented and tightly coupled code-bases makes it impossible to smoothly transition to something new. Often a combination of the two.