I like to say gambling is overall a social sickness, which affects of a social activities and personal life too.
You are treating this subject as if anyone that gambles once will get addicted to it and that is not true, you are treating gambling the same way as drugs and they are not the same.
Are there some persons that got addicted to gambling when at first they gambled for fun? Yes
Does everyone that has gambled for fun become addicted to gambling? No