I guess it is easier to spend a money that is won in gambling than a money which is paid after a day's hard work.
That depends on how you treat your gambling activity, if you are into business, you would consider your profit as part of your income and you will not spend it right away as you know you are still for a long term and you need to ensure you will last til th end.
Its' different to gamblers who gamble without considering a long term journey because they don't account their winnings and loses.
There are always people who are like that. I mean people who are not going to easily let go of their gambling winnings because they are taking into account their previous losses or their long term spending. But so far in my gambling experiences, gamblers are generally easy on their winnings. They give tips to dealers in casinos. After winning a good amount they go out of the casino, celebrate by eating and drinking and talking with friends. That is what I and my friends do with a portion of our winnings. But I very seldom do such things with my salary without a special occasion.