Most of the countries actually putting bans on gambling are for religious reasons and that's why it's mostly the middle east region although it's not entirely pin on those areas but I think you get the picture. Other countries are actually utilizing the massive gambling industry which is something that the government are well known for as they always exploit situation to their benefits and one way they achieve this is by taxing the gambling industry which active initiative towards this.
The countries that banned gambling in recent times did not take those decisions on religious background but mostly because they perceive that it is impacting on their population negatively. In other words, they took those steps as a way of helping their citizens deal with gambling addiction. I don't blame them because they acted on their understanding but the truth still remains that not action leads to positive results because this case in question will not stop any addicted gambler because they must find a way of gambling no matter what their government does.