Some gamblers ignore the warning because they are desperate to win bigger money. They make wrong decisions about their gambling which only ends up costing them financially. Greed and inability to control gambling urges are some of the reasons why they gamble with borrowed money, but it is a horrible experience to tell.
I have seen several such cases coming from some of my friends. So far I don't want to tell you much about their gambling habits, but they have reached the stage of make loan for gamble and running away from reality to repay the loan.
It is the desire to win bigger money that triggers them to borrow money so they can continue playing gambling and they can even increase the stakes so they can win bigger wins. But that's just a hope that they don't know can come true or will only be a hope but mostly, they will only add to the number of losses that are getting bigger. And it is true that greed will drive gamblers to spend more money than usual and only because they want to win more money but in the end, they will lose more too.
Borrowing money to gamble will not give you more hope of winning. And if they could think about the risks involved, they might think twice or more about borrowing money to gamble.