So people who work as EMTs or as nurses who have to actually talk to and care for victims, don't you think they'd have the worst PTSD of all? What about people who have to do autopsies?
You're incredibly naive. I'm an emergency physician. I'll bet I've seen more fucked up shit in one week than you will in your lifetime, unless you've served in the military in active combat, and even then I doubt you've seen the outcome of child abuse.
People in my line of work do get burned out, do get PTSD, and do require counseling from time to time, and we only see the aftermath. And we don't actually see the bad deeds happen. It's much easier to distance yourself from the events when you only have to deal with comforting the injured. I've been mugged at gunpoint and been struck on the head multiple times in the mugging, and that had me looking over my shoulder for years. It affected me more than all the other shit I've seen in my life combined.
Autopsies are pretty sterile things. I've been in on a few. Not a big deal. Dead body? Seen lots of those.