Gambling is not something that is by itself wrong its just that people are doing it wrong in my eyes, I think that some people are just also making it bad and wrong.
Gambling is something that can be fun and enjoying so long you are not doing it for the profit.
Gambling itself is not wrong. That is why a lot of country allow casino to be setup. Otherwise it will be totally ban like weed or other drugs. However, casino does give a lot of social problems as people tend to overexert themselves when gambling. These people give casino a bad name.