Honestly people who have the money for gambling this much also has the chance to keep gambling as much as possible. They could simply just ignore all the money it would cost them and keep gambling as much as possible to get there, this is a game challenge for them. Like how you would open up your steam account, pick a game, play there and get an achievement on that game? It is like that for them, because they have so much money that the amount they spend here is nothing to do them at all, it is like game money for them.
This is not really a bad thing, if you are rich and like doing it why not do it?
I think you are right to a certain things but I wouldn't say that only the rich people have the ability to keep gambling, I know some dirt poor people in my place and they are in the gambling house all day 24/7. I wouldn't say it is not a bad thing because that money could've gone to a better cause like free housing for homeless or soup kitchens, there are a lot of problems that these rich people could solve but they choose the vices.