As I am from India, it is illegal to gamble here. Even though there is no specific laws to frame online gambling, people are scared to expose their identity. Crypto currencies are really helpful to be anonymous. Moreover, fast withdrawals and convenience are bonuses of using it.
Yeah same here, in my country indonesia also banned all gambling activity. That's why people here gamble on online gambling. Online gambling is popular here, not only on cryptocurrency but fiat online gambling also popular.
That is because crypto currencies is not that popular with a lot of gamblers though the popularity of gambling with crypto currencies is improving and developing since there are a lot of gambling sites now that is accepting this crypto currencies.
With it's decentralization and anonymity, a lot of gambler are in favor of using Bitcoin to gamble. Who would not want to gamble and spend money without knowing who is that person spending it, right? But always be careful and responsible on betting and gambling your money.