There are different kinds of person in the world, there are those that will prefer to play nust for fun, and those that are really in to gambling because they aim for profits but if I were to evaluate these two, I think those that play because of profits are quite more frustrated unlike people who play just for fun. For me, I always play not because I want some profit, I play because I try to consume free slots and game offered by various gambling sites, just for the intention of fun.
If a gambler's reason why he gamble is to earn its like giving away your money in gambling because its not easy to win and you're more likely to lose (depending on what games you're playing). Because of the money involve and how easy it is to become rich if ever you hit the jackpot many people are trying their luck and spending their money due to this hope. Well we have different reason why we gamble but have a limitation so your life wont get wreck.
If you are targeting to make more and more money via gambling, then it is obvious that you will fall addict to it sooner or later. I dont think that if a person gets disheartened due to a loss it would be enough for him to quit gambling. It has an alternating effect most of the time. People try again and again to overcome their flaws and regain the lost money through gambling and this leads to unending addiction.