Yes, certain government agencies appeal to professionals as vocations rather than jobs. I have a friend who joined the FBI straight out of college. They don't EVER chat about their job, but I GUARANTEE you a private-industry offer at a significant bump in pay wouldn't make them flinch.

CDC? Every day you go home believing that you are part of a machine saving thousands of lives. BATF? Keeping guns away from terrorists.

And it's not a self-delusion. They ARE doing good things, even if the agency isn't perfect.