Rich people are humans just like the poor, they both share same brain. Everyone wants some extra funds, but that shouldn't be generalized as the reason why most rich people go to the casino. Some could be for fun, while others go for funds. The reasons definitely will differ, although the general population thinks that gamblers who have huge funds, only get entertained in the game. They're high rollers and the money they lose isn't small, it also affects the rich person. On the contrary, money is not wasted in the casino, where we gamble is not different from other places where we pay to get a service. Gambling is for fun, yes, and whenever a person is getting its opposite, he'd think he wasted his money. Nobody feels great after purchasing things he doesn't need. But it happens each time we go the mall, provided we have enough cash, we'll end up buying products that doesn't matter to us or wasn't on our mind previously before entering the mall. So, when someone goes to the casino with lots of money, he could go home feeling he wasted his money. Yet, he didn't, because he decided to do it. Nobody pushed him to wager expensively.
Whether rich or poor, everyone has their own reasons when they decide to go to a casino, whether it's to find entertainment to unwind after a long day of work, or just to test their luck. But there is someone who stupidly comes to a casino with the excuse of making a profit, even though he comes as a visitor, not as a casino owner or employee. They forget that gambling is full of uncertainty, and there is no guarantee that every time they gamble, they will win.
While the decision to bet large amounts is up to each individual, it would be stupid if we spent a lot of money on something we are not sure we will get. and I don't think anyone feels happy when they find they have lost a lot of money as a result of the gambling they do.
Your last paragraph is interestingly the truth because people gamble hoping to win big, not realizing that it's uncertain whether they'll win or not. What excites people is different and unique, but nobody will ever claim to be excited by losing money each time they chase a loss. The excuse or claim that gambling would yield more wealth, is based on what they heard or saw before joining the gambling niche. While both the rich and poor have their unique reasons, newbies seem to have similar reasons, unless told the facts or truth about gambling. It's quite burdensome to get new gamblers to realize gambling is a place to earn profits. Many people have never gambled for fun, that is, they never had complete excitement while gambling.
Because of the uncertainty in winnings, such players tend to get happy shortly after winning and end up going home sad because they lost it all again. Such anxiety develops into a bigger emotional challenge that the player would have to deal with this form of gambling for a long time, till he falls into the trap of addiction. While everyone claims to be excited about gambling, whenever asked. It's crucial to open up when the fun is no longer there, the problem could be around the corner. A writer once asked random people leaving the casino if they enjoyed the game and they gave him no single response. The anger of losing all that money back to the casino leaves them not wanting to say a word to anybody. That's quite a wrong gambling behavior.