I put it in quotes not to be "ironic," as you say, but to set it apart as a specific cliche expression that people use when describing the police to dramatize what they do and emphasize the risks that they take (those risks are statistically about as much as a construction worker and significantly less than a landscaper or a garbage collector.)

Ask yourself why you've never heard someone talk about loggers "putting their lives on the line."

In a way, you've actually proven my point that the lives of police are overvalued in American society. Just the mere suggestion that the risks they take are exaggerated is enough to cause you such visceral outrage that you have to quit reading.

Unfortunate.