I'm not sure the origin of it but I think it had to do with the types of jobs they were doing .
Can't speak for all the services but my sister was a nurse for decades in emergency and the pay was pretty ordinary . She did nightshift work for years because it paid better . Unfortunately because she was on nightshift she had to deal with the drunks and drug bags as well as the Saturday night car accidents etc .
If they are getting paid better than the ' average ' worker it's because they deserve to be . Police , nurses and ambos have a pretty tough job .
