If a country's gambling industry has the potential to compete on a global scale, then there will be many potential foreign investors who want to invest in it, and I think the government has no reason to reject it. In general, if foreign investment in a country increases, then the country's foreign exchange reserves will also increase (especially for developing countries) and of course, this is a benefit for the government.
Of course, this step can help the government get more money from the gambling industry and with it can also increase the state income which is included in the foreign exchange reserves. If gambling in these countries is legal, then the government has no reason to reject the idea.
I agree, gambling is a viable part for many countries. Banning such activities is not a good idea in my opinion. The government is not only profiting directly from gambling through tax revenues, but also indirectly through higher demand in other sectors. Gamblers need to sleep somewhere, need to eat, need some leisure time. There is only positive effects. And if you win big in a fand you actually want to spend that money and treat yourself with something nice