Only Muslim countries and other countries that have strict restrictions against gambling but the rest of the world gets a lot of profit from gambling industry. The only cons that I can see on gambling are when it was freely open in 3rd world countries which result in many life destroyed due to gambling addiction. People living on first world countries like US can easily get back on their feet with the proper support of their family since they have a huge financial capacity to recover compared to a poor country where jobs salary is very low and sufficient only for their own daily needs.
Monaco is the best example for moderating gambling while getting profit on it at the same time without involving there citizen on gambling addiction. This idea should be implement in poor countries to fight against gambling addiction.
There are many non Muslim countries also where gambling is strictly prohibited like Japan, North Korea etc. In gambling you can lose your all money in days or weeks and it doesn't matter how much financial cushion you have, you can easily end up on footpath after losing all your money. There are such examples in developed countries like USA and Europe. You cant say people living in advance countries can cope with gambling well.