I think this is because are hoping to recover from their loss. This is what make casinos rich : people do not accept their losses, and if they do so, they are exposed to lose more.
Well that it what makes 95% of the casinos and gambling sites to be super rich and always stay in profit no matter how high a person wins his bet.
The biggest problem of gamblers is to recover loss which ends up making them in a huge debt.
I think there are only 2 ways to help those kind of people :
First if you are not a gambler and go to some casino and be like you are going to gamble for fun only then please resist yourself because I have seen so many people who go ti casino's for entertainment and end up getting addicted to it.
Second if you are already a gambler and are in a loss and invest again and again to get your loss back then please don't go you are just increasing your losses.