I agree with the article's point that "we" are naive. Even in domestic incidents like the school shootings, the society as a whole does this eyes-glazed-over denial routine where "things like this don't happen" or "aren't supposed to happen". The consequence is total lack of effective action, because preparing for the fact that these things obviously DO happen would require acknowledging and coming to grips with that FACT that people do go out and deliberately kill people who don't deserve it. It might also require people to consider the issues of guilt and blame. As long as these are 'isolated incidents' and due to 'mental illness' then we don't have to face the reality that some people are evil and are motivated to kill other, innocent people.
The problem with this in America is that "addressing the problem" always addresses the wrong problem, ineffectively, with a high cost to individual rights, but this is because of the denial. It's obvious that TSA does not actually expect to find explosives, because their procedures are incapable of dealing with any explosives they actually do find. It's obvious that schools don't actually expect to deal with an armed shooter, because the procedures are incapable of dealing with such in any way. This situation arises and remains because in a society which is in the naive/denial stage.
A society that is used to people killing for ideological reasons has been pushed past the denial stage and into the "address the problem" stage. The sooner we push past the denial stage into the reality stage, maybe we will get some rational cost/benefit analyses on prevention measures.
I'm not against having to have my trunk searched before being allowed to park in a mall parking garage. I just think that it needs to be the mall's security requiring the searching, and not the government.