An article in Christian Post.com on the supposed influence of pop culture on violence amongst teens illustrates the problems caused by the denial of Original Sin. People need something to blame for such senseless violence such as the Mall shooter and the Church shooter, but because they deny Original Sin in order to maintain their fantasy of deciding for Jesus they blame the media. Why? The media is safe and blaming them means they don't have to look to closely at their doctrine, because to acknowledge that the people themselves are responsible for their own actions is dangerous to their world view.
To state that the people who perpetrate these atrocities are solely responsible for their actions means they must admit to an innate inclination to perpetrate murderous actions and that my friends is dangerously close to saying those evil Catholics were right. We did inherit sin from great grandpappy Adam. The people in the media are not responsible for this men's actions. Those men are responsible for their own actions.
Now, likely these men weren't firing on all cylinders. They probably did have something going on that impaired their judgment, but the root cause for that impairment is sin. If Adam had not eaten that fruit we would not have people who were a few fries short of a happy meal. We would all be perfectly tuned God lovin' people. So, once again sin is at the heart.
Here is the kicker. Why do people like violent entertainment? Sin.