America is so weird. This old fart would rather kids saw people being stabbed and exploded than hear a few shits and fucks? I get that a lower rating = a wider audience, but it's still lame.
Not making a judgement either way, but if you look at it from their perspective, there is
some logic.
Some people find words offensive. A word being spoken in a movie is still a word. To the person who finds it offensive, it's basically exactly the same as hearing it in real life. So the offensiveness of it isn't lessened.
Violence in films, though, is complete fake. There's obviously a huge difference between real violence and fictionalised violence.
When someone screams obscenities in a movie, they are still screaming obscenities. When someone stabs another dude in the face in a movie, they aren't actually stabbing a dude in the face.
I imagine that's the reasoning.