What? You don’t think that anyone is motivated by their final acts by the idea that it will bring them glory or infamy or otherwise influence the way they’re thought of after they die?
As far as “blame” goes, that’s a tricky subject full of semantics, so I’ll say it like this:
If the media did not go into a frenzy over mass shootings, shift their coverage predominantly to that incident, have experts on speculating on the psychology of the perpetrator, give attention to their grievances or manifesto, and basically make them the most famous person in the country for a couple of weeks, would there be fewer mass shootings? Yes, significantly.
Did anyone see how the Canadian news handled the parliament shooting? They took the high road, said they’re going to focus on what happened and on the victims, and not give the perpetrator of his beliefs air time, not even to mention his name. It was such a ridiculous contrast to the absurd circus that the American media runs whenever there’s an event like that here that I don’t even think they’re in the same business. American journalistic ethics are in the toilet.
People who snap and do this sort of thing often think the world is ignoring them, or unfairly victimizing them, and that they’re going to get their revenge. The world is finally going to see how wrong it was for neglecting/ostracizing/whatever them. They absolutely crave that level of attention. If the person looks on the media frenzy around past events, and thinks to himself “yeah, that’s the blaze of glory I’m going out on”, he’s much more likely to actually commit it than if the incidents were reported responsibly, without a focus on the perpetrator, and with far less glory and infamy.
Changing the way the media treats these incidents would actually be the most cost effective way, by orders of magnitude, of preventing these sorts of things. Merely a few organizations would have to agree to not give the criminals the infamy and attention they crave, and you’d see a significant reduction in these events.
If you believe the media only gives the public what it wants, then you can do your part by not getting off on macabre coverage of these incidents. Shit happens, put it in perspective, and don’t gobble up that news coverage obsessively to try to see people speculate and pick apart every last aspect of these incidents. The attention you give to these people is, in most cases, exactly the sort of thing that drives them to do it in the first place.