Gambling has no effect on a country's reputable status. The mere fact that countries participate in sporting activities implies that citizens will gamble on those sports, either for entertainment or to make extra money. Some people travel long distances just to visit a country's casino, which in the long run generates revenue for the country.
The bookies also pay taxes to the government, which, along with other revenues generated, is used to further the country's development. It is important to note that, when viewed through the lens of the international system, gambling is not one of the indices that affect a country's image because gambling is done on an individual basis.