It must be due to religion. In Muslim countries, gambling is illegal and although there are still people gambling, it isn't as vulgar as right in a public place. Same on countries where governments are prohibiting gambling, its effective in making people afraid to gamble and they are not going to be addicted to it.

Countries with more gambling addicts means the laws aren't that tight.  I live in a country where gambling is rampant and allowed so more people are up to play all night.