Teenagers pressure eachother too often that when one of them begin to experience success in life too early, others begin to get envious and what to do something to get money so they will not be left behind.
Sometimes, unfortunately adults are still vulnerable to this. Obviously they have better grasp at peer pressure but adults are also envious of their peers. They are not immune to wanting the easy route of money earning.
Gambling is one of the easiest things that they will decide to do and they rush into gambling without having the experience before and they are not also patient because they want to meet up other teenagers that they are friends with.
I guess the difference between adults and teenagres is what they will do to the money they earn from gambling. Teenagers are still very much irresponsible and still have no concept of financial responsibility.