It reminds me of a piece on NPR about family members of the victims of homicide. One person pointed out that it's common fun to host "murder mystery parties" but nobody would ever think of hosting a "rape mystery party". Similarly Grand Theft Auto is fine, but Rapelay is highly controversial. Obviously part of the reason we're less sensitive to some types of violence is because we have less violence (I think many people have a friend that was raped, but very few have a friend who was murdered). However, even if this detachment comes from an increase in non-violence there are still effects of increasingly conflating violence with entertainment.