Why is it so much easier to show violent values to our children than to sneak in good values?

Somebody elses question got me thinking.

Why does violence still sell nowadays? Back when it was unusual to see a violent crime portrayed on TV or described in a song, there was a hard edged novelty to it. We labelled the songs "Explicit Lyrics" or whatever fit and tut-tutted. Now that criminal actions have permeated every form of entertainment, when will we cross back across the line? How many more school killings have to happen before we can put a few more Dumbo elephants into our kids lives and a few less Dum-dum bullets?