I get this all the time from defenders of the military. Most recently because I posted some sick military training chants. A woman writes in disagreement: "I absolutely do not believe this! I have had a father, two brothers, a niece and a nephew in the military (niece still is) and they never chanted anything like this. No way Jose."
Well, I absolutely do not believe this. I think your father and brothers probably uttered chants that were just as sick. They just didn't tell you about it.
In the past I have gotten in so many words:
My father never tortured anyone, so it doesn't happen.
My brother never killed a civilian, so it doesn't happen.
My uncle never urinated on dead enemy soldiers, so it doesn't happen.
My grandfather never cut off a dead enemy soldier's body parts, so it doesn't happen.