I agree with this and always use it in my life. I gamble occasionally, but usually use a few dollars for a bet here and there. So when I lose, it's no big deal, and when I win, I usually just use this money for my future bets. I think it's a realistic and healthy relationship with gambling. I gamble for fun, so I'm okay with losing a bit with it. I don't expect to have big wins, let alone win on a regular basis (earning money is what job is for, not gambling).
As for people working in casinos, I don't think they spend their time analyzing the gambling behavior of their players. However, there should be academic paper about it that might shed some light on it.