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.
It was restricted on muslim and similar countries because for them gambling is a sin. Not all can get a lot of profit in gambling, I mean the regular individuals but for governments yes they can get a good revenue with it. The cons you are talking about above is not totally a con but it can also be a pro to some because by allowing gambling on their country, it also open opportunities for the people, what I mean is jobs.
Also not all that engage in gambling are going to be addicted with it but most are only using it to pass the time and to relieve their stress from the whole day of working. If they are lucky they can win, and gambling can provide extra income to them.