I guess its the other way around. Rich people who gamble just for fun, most of them have connection from the managements or owners that was invited to that place to play for entertainment and fun, only few of then got addicted, and rarely go there because most rich people knows how gamble works and have discipline when it comes to money. Although there are few who got just taste of being rich without having solid principles and discipline got hooked on gambling.

While the poor to high income got the higher chance of getting hooked on gambling, i remember one of an engineer with lots of projects earning him millions got addictive casino slots and got bankrupt in a sense that he also use the money of some of its latest project hoping it will be doubled