It is true that some of the characters speak coarsely. That is because people speak coarsely in real life. Especially soldiers and hardworking men speak coarsely, and even our most sheltered children know that. And we all know, too, that those words really don't damage children much. They didn't damage us when we were young. It was evil deeds and lying that hurt us.
Kurt Vonnegut Jr., If This Isn't Nice, What Is?: Advice for the Young
children, cursing