@tripu Murder is a destructive act, with death as the end goal. Sex is a creative act, with pleasure and birth as the eventual end goals. The shock value of rape is that of a creative, loving act (sex) that's been perverted to destructive control.
It's the cognitive dissonance that occurs when observing the transformation of the positive into a destructive force that provides the added shock value.
In many ways, it's the same dynamic as the difference between death by a firing squad and mutilation through torture. The latter is less destructive (the victim is still alive), but vastly more cruel, as the victim has to live with the injury forever. The same can be said of victims of rape and pedophilia.