I think the fun in gambling is putting a certain amount of cash and getting the amount in certain multiple rate, gambling is fun when you win either in real casino or online. The part where you lose is usually the bitter experience , most especially if the stake is high.
If people play for fun then it is fine but the moment they want to just make money from gambling either on site or casinos is the destruction which could happen and can destroy them self and the relations ship with others as they will need money to keep playing.