The truth is that gambling is a game of emotion and psychology, at first it looks like you aren't serious about gambling but later after some win or loses you become emotional, you think of recovering your lost amount, and this makes you to keep Gambling even when your mind kick against it, likewise when you are wining you become emotional, thinking of possible way to become wealth from gambling, and this leave you with gambling more than what you can't afford to lose, and that's when you become psychologically deranged. So gambling is a mind game and whatever money is involved, it must surely involve emotion.
This is not just about gambling, but making something a hobby somehow makes you loose interest in other things and weaves your attitude around such hobbies. If someone makes gambling a hobby, then he's likely to loose focus on other things, especially as we all know gambling can be very addicting. Gambling is now going through OP's cousin and as a result is reworking his psychology and rational idiosyncrasies and he is now thinking and acting with gambling mentality, I advise him to stop gambling since he is gradually loosing himself to it, he needs to quit and that must happen now before it is too late.