Thanks to the joblessness following the Crash of '08, America's young have become a "lost generation" of sorts. Not the good kind of Lost Generation, the kind with Fitzgeralds and Hemingways. More the kind that gets in shouting matches over whether Daredevil would benefit from Lasik surgery.
When you don't have a job after college, it is predictable that your maturity will also be put on hold. You can remain irresponsible, sheltered, flaky, and hold tight to all the idealistic teeth gnashing programmed into you on campus.
Not only does this career delay mean not having to enter the workplace and adapt to its discipline and compromise, it means not being exposed to tyrannical HR departments; whose power and wingnuttery are the predictable result of elevating political correctness to a religion. If this lost generation got a dose of today's HR National Socialism perhaps they could finally see where their unthinking "social justice" boosterism leads.
Today's lost youth were also weaned on social media crusading and shaming. (Their age is also the age of campaigns against Internet bullying, which somehow isn't called bullying when done in the name of political correctness). They've grown up in an age where it's quite normal to form an Internet lynch mob to attack those with whom you disagree, and the Internet comforts of anonymity and distance only embolden these attacks. When you can bully others without consequence and in the process convince yourself you're a soldier fighting for the "right side of history," of course you're going to double down. That these bearded babies have plenty of free time to obsess over villain-slaying superheroes with secret identities probably fuels this fevered stone throwing.
It is beyond obvious that leaving a generation to continue stewing in the cupidity of their salad days long after the leaves have turned brown isn't going to result in nuanced converstion. So if you were wondering who's to blame for the shrill, sophomoric flavor of social media (and ultimately youth level) discourse, you should probably start with Alan Greenspan.