We can look on this from different angle - those who record gambling activities, might realize how much they have already lost, and their wish to play back that amount might grow stronger. It will be something that spurs them to continue, to try to win. A number that will often pulsate in their mind and remind to gamble. A reminder that will alarm them to always have money for gambling.
The record carried out can also be a reminder that too much has been spent on gambling. and they should be able to regret why they wasted large amounts of money and they can stop.
but what happens is not like that, I'm sure more gamblers don't consider recording all their expenses in gambling. gamblers will always have money to allocate for gambling, there is no need to record everything because it probably won't have much of an impact.