I've seen one person gamble responsibly. My boss takes a budgeted amount of money to Vegas for gambling every year ($800), and expects to lose it all, but have fun doing it. It lasts him about a week. The casinos pay for lots of lodging, food, and entertainment while you lose it. It's when you hope to win that you are in trouble.
Casinos should be treated like pinball machines. I've thought that casinos could could nip addiction in the bud by selling chips, but not redeeming them (like pinball). However, any casino trying to pioneer this would lose a lot of addict business.