If they are both able to earn their own money, I think they can both continue to gamble. They can also share household expenses. I think there is a possibility that both of them might get out of control, but it is not a sure thing, and both of them can manage to act responsibly. I don't think it's right to have prejudiced thoughts against this imaginary couple. 
Well, I find this very difficult to resolve. We cannot force a person to quit gambling. While we are gambling. If economic conditions are good and both people know how to control themselves in gambling and have a lot of free time. Both could use some time to gamble. If either of the people has an addiction and a difficult economic situation, I think both should quit gambling. We cannot gamble in front of people who are addicted to gambling, and they will not be able to go through rehab.