It's true that if they're going to waste their money, they should do it somewhere else. But the thing is that we all have different ways of enjoying our money but it's also true if you're going to gamble, as you know that you'll just lose, you have fun on it as well.
I personally gamble just for fun, and we know very well that the table always wins no matter what. and it would be very hypocritical if I didn't want a big win, everyone who does gambling activities definitely wants to get a big win. despite all that, if someone always aims to win in every gamble, I think he will end up disappointed and will even experience a lot of losses. I changed my mindset in gambling just to have fun and if I was lucky I got prize money from fun things.