If firefighting were done like policing, firefighters would go cruising around looking for fire. Or smoke. Instead of actually spending most of their active time rescuing people and property, they would spend most of their time writing tickets for candles, cigarettes, possession of lighters, or anything hotter than allowed. They would have quotas, and if they couldn't fight fires, they would make their own work.
Smokers could be shot dead, with minimal warning, since the firefighter was "only doing his job". And, where there's smoke, there's fire.
Any fires reported would draw firefighters from all over, who would stand around and watch it burn, since they "just want to go home at the end of the shift", and firefighter safety would trump all else.
A firefighter discovered to be an arsonist would be given a few days paid vacation before being found to have acted within departmental policy. He would be reinstated and anyone who spoke out for the victims of the fires he set would be hated and threatened. He would get rich from donations collected during his vacation, and his victims would be said to have deserved what they got.
And we would be constantly told how heroic they are, and how without them, the entire planet would burn to a crisp.