Personally, I don't think it's necessarily "society" that's responsible.
I think blaming it on society is just a knee-jerk easy-route answer, just as poorly directed as blaming it on the weapon the individual chose to use.
Neither is to blame, and blaming either one (or even both) will just lead to frustration, repeats of the event, and in the end there will be no actual resolution.
In reality, the society I live in (good ol' USA) does not condone this behavior. We don't appreciate it, teach it, encourage it, minimize it, or excuse it.
In reality, the society is just the sum of the individuals that make it up, and the individuals are just the product of the environment (society) they live in. The society and the people that make it up, are synonymous.
The people that do these things are not "normal", i.e. they aren't synonymous with the society. They're a statistically infinitesimal faction within the society, but they most certainly do not represent the society, and the society most certainly does not represent them. Blaming the greater whole for the extremely rare out-of-the norm defect is insane and irresponsible. It's going to get people killed.
Since they're not a "normal" chunk of society, they aren't going to be effectively controlled by the "normal" controls (laws, morals, fears, and motivations) that the rest of the society is controlled by.
Forget the lame-azz easy-route scapegoats (guns, laws, society) and please begin looking for the real root of the issue.
This tiny faction of nutcases feels tiny, isolated, frustrated, and ignored. They want fame. We're giving it to them.
The longer we waste time looking at the wrong things (and using them as leverage for political gain) the more society (and the good folks that make it up) will suffer. It's time to look outside the box!