Those who cannot accept defeat in gambling are some people who gamble with the aim of making money, and I am sure when they experience defeat they cannot accept it and what they get is heartache because the results are not in accordance with what they expected.
Anyone who fails to accept defeat or let the money they have already lost to go, they will learn in a hard way and this is one of the reasons why gamblers falls into addiction because when they can't let go of their losses it becomes a problem because they will spend more money on the ground that they are chasing losses which will further lead to more complex situations because since they have already lost a lot and couldn't recover, if they now decide to give up on their losses the memories of those losses will begin to ring in their head and they become emotional.
The difficulty of accepting defeat is actually more about responsibility, meaning that it means they are not responsible gamblers but yes it can also be said that they are most likely trapped in addiction because usually addicted gamblers only want to win and not lose, and yes you are right that in most cases they will usually end up losing more money because of the act of chasing losses which usually they will only stop when they have run out of all their money.
On the other hand, this is the reason why gambling must be done based on the right and proper understanding, because only that can help gamblers so that they avoid addiction and various other impulsive actions.