I believe that it is necessary to build logic according to Maslow's pyramid - if a person is provided with food, security and self-expression, then he will look for entertainment for the soul and brain, I mean to look for adrenaline, as mentioned in the previous post. While it is the poor who will only think about the result in the form of winning money in order to correct their poor monetary situation.
Maslow's pyramid is a concept of what individuals should achieve in sequence, following an hierarchy, to achieve balance, organical homeostasis, so they can finally start drawing their road to self-realization, which is the top of the pyramid, once all other needs are already fulfilled.
However, what we see for real are individuals who aren't able to fulfill basic levels of their pyramids. They don't have security and stability, they don't have love and belonging, their self-esteem is weak. So they appeal to disfunctional practices as a mean to escape from their harsh reality.
One of these escapes consist in gambling addiction. The disfunctional pleasure they have when gambling without limits and control works for them as a brief relief from the pain and frustration of daily life, especially when we take the financial aspect into consideration.
Since they are frustrated for being broken (respective to the second tier of Maslow's pyramid), gambling becomes the escape because it theoretically can make them rich.