Gambling can never be banned - it is the life support for the people and sometime it is very helpful for the economy for bringing in the revenue.
However even in the countries where gambling is banned - now they have found the ways to gamble and there is no stopping. People would not let the gambling banned.
In those countries, they saw the harm of gambling and decided to completely banned it to make sure they will lower the risk of their people's depression because as we already know, there are lots of people who lost compared to winning when it comes to gambling. But some people are just hard-headed and pursue their high-risk hobbies even though their governments forbid them from doing so. When they messed up themselves, they don't have anyone to blame but their own desire, and their government are free of what they have done with their life.
I don't support that gambling should be banned especially in this modern world of liberty. Internet and especially Bitcoin has brought some kinds of liberty and it will not make sense that government or authorities will deprive people this liberty. The best that should be done to gambling is some kinds of regulations that will protect children and ensure that number of addicts are reduced.