I think that, nowadays, youngsters have many things, too things. Parents give them all they want and they don't need to work hard to obtain anything.
They grow in this plenty, so they look for activities that can represent an incentive for them.
Also, I think this abundance of material things -obtained without hard work- makes that teenagers don't value anything, included their lives. This could be the explanation of their choice for doing dangerous things.
I'm not part of a generation who grew in plenty, so when I was a teenager I did things more quiet and innocent that what youngsters do now. For example, when I behave badly I used to ring bells and go away running, or make jokes by phone.