Yes, I believe that gambling is something that triggers dopamine in the reward centre of our brain. You might look at it as a business or entertainment but I believe that the whole system is linked with the reward centre and winning makes us happy because it gives us the pleasure of feeling superior to others and due to aggressive human nature, we give our best in order to prove that position and defend the title of winner. This process is entertaining for those who perform better than others but the case might not be the same with the losers. However, it might be addictive in both cases.
Well the feeling of gambling is a kind of utility and you want to get your utility maximized to the point of saturation and there are two possibilities at the point of saturation. You get your return fully maximized or get a downward graph of utility. A win thus defines utility maximized and a loss results in utility minimized. But since it is a game based on probability and randomness plus strategic moves, there is always a chance for you to win.