Well, he is actually very wrong. Percentage of rich people who gamble are the rich folks as they have even bigger money to funds their gambling activities to their taste. You see a lot of these rich guys in physical casino dropping a lot of deposit and even when they lose, they don't give up as they know if they win, it will definitely be a jackpot.
Lower class gamblers, usually knows how to manage their funds and even their gambling activities, they bet with little money and hope to get bigger ones back. The truth is that gambling should not be used as a way to earn a living but you can make good profits from gambling. These winnings have changed a lot of peoples lives.