There are a bunch of reasons for that decline, but a big one is that young people simply have hobbies that don't bring them in physical contact -- get mad at somebody over Facebook, and nobody gets stabbed. This is why online harassment is so rampant and also why nobody gives a s**t: sending email rape threats is what they want the sociopaths to be doing -- because in reality they're still just staring at a glowing screen, motionless. Did I mention that when you introduce Internet porn to a population, real-life sexual assault goes down? That's where you want the deviants, too -- motionless, perched in front of a glowing screen, molesting a wad of Kleenex.
So now you're kind of rooting for it, right? But remember, the system wants to pacify you, too. The system needs impoverished customer service workers, and it needs those impoverished customer service workers to be OK with that situation. And the way you pacify a person is by reducing their life goals to a list that's one item long: feeding their addiction. An addict can become OK with anything -- their status in life, their dead-end job, the system overall -- as long as they're getting their fix.
After all, there's a reason society is coming around on weed legalization -- it may not have the chemical addiction of meth, but it sure as hell makes you OK with sitting motionless on your sofa. That's why I find it hilarious that weed is such a symbol of hippies and the counterculture. If you're working all day to make money to buy weed, then spending your free time stoned on the sofa, you're the perfect drone. Now tell me you don't know at least one person who's fine with living paycheck to paycheck, as long as they can dominate at League of Legends every night.
That feels like a tragedy to me. Remember, those pleasure centers in the brain we're letting someone else hijack were put there for a reason. We evolved to feel a high from a successful hunt, or winning a battle, or securing food, or making a friend, or finding a lover. Improving your life, in other words. Once they can decode how to induce those feelings of bliss with various combinations of chemicals or stimulus, the game is over. The chemicals will always be more attainable than the actual pleasures they're replacing.
Who needs to try when you can get food, drugs, and robo-genitals delivered right to your door?