Although some kids do get a good parenting background, but sometimes they get tangled with friends influences. They can have a different lifestyle outside, and when they go back home, they pretend to be good kids. But it depends on kids and their decisions; anyone who decides to be responsible will heed what their parents teach them. Although what you say is also true, some parents are mostly concerned with their job and forget the family responsible, which is mostly concerned with raising the children in a way they should grow. Again, gambling addiction can start at any age; it doesn't matter whether one starts their gambling activity at a very young age or not; once someone just decides to lose self-control over doing something, it becomes an addiction, which can lead to other problems for the person.
We are aware that some gambling addictions started from the young age, and jids that are exposed to gambling at early age may struggle with addiction later in the life since when their were introduced to gambling their are not mature enough to make good decisions.