Of course you are right because most people especially some parents always misunderstood the whole idea of educating there children about gambling because just like you observed in as much as is very important to teach our children things they shouldn't venture into but we should also consider there age because there is no way they can expect a child of 5 years to still remember what he was taught when was five.
So perhaps a child with that age should only be well monitored and guided so that he will never be influenced by anything and perhaps when he or she has gotten to the right age then the parents can now educate them knowing fully well that if they failed to teach them they will eventually learned it from outsiders which is going to be very bad for them because they wouldn't really understand how to control there emotions towards it.
Of course, if all the parents are at home, you can be sure they will supervise or guide their children well. Even though we guide our children well at home and even though we forbid our children from doing things that are not good, outside we never know about our children's relationships or friendships. Sometimes it is this association or friendship that makes something happen Our children may experience changes or fall into social circles out there following their friends. Usually at a young age these children are curious to try something they have never done in their life. Usually you can be sure that they will hide their activities from their parents. Yes, this is a worry for every parent.