Excess of anything is harmful and gambling is no exception. In fact most of the problems associated with gambling arises when they tend to overdo the same things and end up losing a lot. If they dont chase losses and be happy with whatever wins they have then it does not give rise to any problem other than your greed which one can control. After all gambling is not something profitable for the player and one must gamble for fun to be happy and not greedy.
There are many things in our life that are not right. And I can call gambling to be one of them. You know but you can't get away from it.