There a different thing how do the parents will let their children grow up that's the reason there's guidance barely needed to upon growing up by the child and seeing that this kind of thing is normal in playing gambling they think it is just okay that's the reason why some of them getting addicted because it is normal thing to them because they see already in their parents activity, if you are responsible parent still it is good to let them know your child what is wrong and right so they prevent getting the same scenario as you that part of gambling habit.
Relationships can be so overrated and so disappointing - sometime parent don't know how to treat their children.
Most of the kids dont make friends with their parents. And Parents are busy in their routine. So they ignore them - that is how the circle moves.
There must be a reason on why kids rebel and won't obey their parents. It could be because their parents have done something bad in the past or like you said they are busy and they lack of time or attention for their kids but not all kids are going to remain like that forever. If parents learn to regret and admit their past mistakes then kids can too. They will realize soon that their actions are wrong and they will go back to their family and now serve their family better.
This sounds like a happy ending but it doesn't mean that we will follow it as a parent. It would still be better if we are responsible for our kids or to our actions as early as possible.