Biggest difference is most firefighters generally don't even get paid, it's volunteers waking up in the middle of the night, driving to the station, putting on gear and responding for the love of the game.

Gruff assholes yeah, but everyone I know trains two hours every week on top of a few classes a year. Also the whole point is the expectation that you're responding to a dangerous situation. Too many times I've seen bystanders do dangerous stuff and yelling at them is the fastest way to notify that they are walking into danger.