Let's use a business for example, if you continue putting money into a business and it's not flourishing but failing. One good day, someone gave you a contract to supply some items which you are dealing on. After the supply, you got paid. The first thing that will come to your head is going back to the book that you recorded all the expenses on keeping that business running till that day, to see how much you have recovered. That's when you will know if you are at loss or not. This is the main reason why you need to gamble with little amount of money that you can afford to lose, so that when you win big, you've won the casino.
You are comparing the approach of investing in business with gambling? I don't have a problem with gamblers counting all their deposits, it's good enough for self-reflection after a loss. Maybe it would be good enough to count the difference between wins and losses. It all becomes a process and habit of the gambler. But comparing it with investing in business, it might be something different. I'm afraid some gamblers will think that gambling can be calculated like we invest. I understand what you mean.