I don't think there is people richs from gambling. Even if the gamblers win big amounts they will start gambling again and can lose it in seconds, because gambling is addictive as known
There are people who are becoming rich with gambling but they are very few. And those are the people who have business in gambling industry. But if you are going to ask me. I really not make some good profit in gambling unless someone is going to give me capital from their pocket. And it is going to depend on me if I am going to grow it.