Maybe young Americans need some place that they can go to let off steam?
The US is an increasingly belligerent society on the roads and everywhere else it seems, ... people willing to shoot others, drive them off the road, or play "chicken" in autos on the interstate at 65 mph (~80 kph). I see the later about once a month on my commute to work, so that may be the form of blowing off steam. Not that we have a monopoly on mass murders as tragedies in Scotland, Australia, and elsewhere have shown, but it usually takes a lot of payola to move our national Congress, unless they could possibly be threatened by violence, as the response to the McVeigh bombing - try buying certain agricultural chemicals in the US - or 9/11 shows.
The irony is for all the talk from some of our Congress-critters about how having concealed pistols makes people safer, one wonders why then Congress doesn't allow them in their chambers?
Our own Capitol Hill shows what a "gun-free" zone really should look like. All entrance points, only through a metal detector, with armed law enforcement at the ready (donut break later). That's what all federal buildings have had also btw since the late 1980's when I had to enter for business (miss the line and they'd come down hard like an episode of Miami Vice).
It's a big enough country that sane, non-violent people should be able to own firearms - some people still subsist on squirrels - but school districts should guard their most vulnerable public spaces (namely schools) like we guard Congress, ... maybe let some capable administrators carry, etc... Add that in a diverse country like the US, we have very different urban, suburban, and rural areas, with different patterns of crime/gun-ownership ... so those school districts with the state need to be the lead in figuring it all out (once the board members are done doling out no-bid construction and testing contracts to their buddies, that is). Also we need to reverse Reagan's emptying out of the nation's loony bins.