It doesn't matter if they are rich or poor people could still get addicted to gambling it only depends on how well they could control it and how much they could spend on it.
For me the only difference is the amount that they could risk in gambling.
They might not be addicted to the profit or gains but the feeling of winning or being a winner hitting big or something else.
Some are not addicted to the being a winner, they are addicted to the satisfaction they feel when gambling, it doesn't matter whether they win or lose it's just something they can't control. People like this would go to any length to get money just for them to fuel their gambling addiction. Both the rich and poor people might go through this, it's kind of a mental disorder and it takes a lot of discipline to stop