He still argued that if he doesn't gamble, he wouldn't be able to entertain his clients well and give them meaningful suggestions from his experience that brings about some of his tips.
A gambling casino worker will be more knowledgeable and also have better customer relations. His experience will give him a better understanding of the game and customers' behaviour. His suggestions can either lead to gains or losses, so receiving tips is not certain
Good thing is that he's starting to take things easy, I didn't ask him to stop gambling entirely because I know from experience he'll not agree easily, he's changing and that's more important.
There is nothing financially or morally wrong with gambling. It could be a good source of entertainment and an additional source of income. The only problem s when it is done excessively or uncontrollably.
Perhaps it's possible not to gamble at all or at least minimized it. I know someone who works on the casino, although not directly as a dealer or in the floor. But he is more on the back office. And he told me that they are not allowed to play inside as they are a employee.
I might be wrong but I guess that the reason why employees might be restricted from gambling might be to protect the business from fraud. These employees can easily connive with other workers to exploit the system through fraudulent means. It could also be a means to protect them from excessive gambling.
Although it's possible that he can go outside and gamble online, but I do know that he is not really into gambling. So I guess he has a big self control and being a insider, he really knows what gambling can do to him and so he stays as much as possible.
Working in a casino and gambling responsibly needs a high level of self-control. It's like working in a brothel as a young unmarried man and not having a sexual relationship with any of the sex workers. Lacking this important quality might lead to unthinkable losses and frustration.