People who are playing gambling are betting on that game for them to able to win
That's the main goal why we are gambling, no one gambles to just lose his money and just say.. "hey it's okay, I am having fun", that's crap.
and I don't know the other reason they do that because they want to be rich or change their status in life to afford everything they want to buy and fulfill their needs.
To become rich is the ultimate goal for some gamblers but others will not even think of that as they are aware of their capacity, they can't simply win, plain and simple. However, there are gamblers who are quite ambitious, they'll try to win consistently and if that happens, getting rich in gambling will just be an easy outcome for them.