Why does indecency have to be a bad thing?

With all this talk about indecency it got me thinking, why does indecency have to be a bad thing and not something we can learn from?  As a society, we spend a large time of lives protecting our children from indecent material, and for good reason, but why don't we try to take another approach?  Instead of hiding our youth from indecent material maybe, we should sit down with them and view some of this material and tell them why it is indecent.  

I saw that in one of the posts, how the blogger's little brother was using curse words even though he didn't even know what they meant.  The boy was just trying to be cool and fit in.  This seems to be the case with all inappropriate material.  They just want to view it, do it, or say it just because they think it's cool and bad ass. 

If parents sat down with their kids and explained why a particular show, movie, or word was indecent and gave real reasons why the material was inappropriate the point might be clearer.  When a kid is told that he can't watch a movie because it has too much violence or sex, the kid is going to want to see it even more than before.  If parents sat down and explained that the material is degrading to women or what ever the case may be, the message could be clearer to the child. 

I understand that this isn't going to stop kids from wanting to still look at adult material, violent movies and say dirty words, but at least what the parent told the child is going to be in the back of their head while they are doing/seeing it.   It's like the sex and drug talks we have with our parents.  It might not stop of from doing it, but at least we will be a little bit more careful and have a better understanding of what we actually might be doing.