Some reasons are:
- Why should they stop when luck is currently taking effect? They will deplete their luck to the max until not realizing that their big winnings are already depleting too. In the end, no cashout happened.
- Now with big winnings already, instead of withdrawing it, they will push for a much higher bet, thinking it will also give them a good result. Since they are now playing with a higher bet, every dead spin is a big blow. In the end, no cashout happened.
That experience will haunt them even while they're sleeping lol.
Knowing when to stop gambling is very important, for a gambler to still be in luck while gambling it only means they won't stop until their luck is up. The gambler can stop at very time that they start to lose but that will be determined based on how smart or greedy the person is. If it's a smart gambler, he will know when to stop and cashout but a greedy person wants to continue rolling the dice hoping to win more and for the same luck to come back, that's why they get busted because of greed. What you said is true, many gamblers have losses after winning big and didn't cashout. The problem is greed and lack of discipline to stop at the right time.