I have been known to silence a conversation in a room by objecting to a joke about domestic violence,  I once had an Aspley chemist's advertisment removed from the radio because it included a joke about domestic violence. 

Violence should never be joked about.  It then trivialises it and makes it acceptable.  Stats say that one in three marriages/relationships include some form of domestic violence.  Anything that we can do to lessen that figure we should do.

has a mod responded to the questions in the OP ? 

has a demo been given by a poster which could explain part of the reasoning ? 

and also If we can post raped but not the word without the 'd' which would make it  past tense does that maybe prevent threats to do it ?

Could that be part of the reasoning ?

It is also the name of a plant & is also used in matters outside of the sexual use of the word.