It is not really that difficult to understand why this happens, people by nature want to obtain the most benefits with the least amount of effort, so even if they could earn money by working hard on one of the many jobs available to them, if they think they can do this with gambling then that is the path they will decide to follow, as in their mind it is way easier to make money this way while obtaining some fun, than by working a great deal of hours on another job.
They have adopted the wrong mindset towards gambling to get high profits, has he ever looked for data on gamblers getting rich from gambling except bookies or casinos? If you find data comparing rich gamblers with poor gamblers, share the link in this thread so we can check the source of the news. So think realistically that the statistical data of gamblers will get worse because they expect high profits but they don't know the financial management to set the lowest limit for allocating funds for gambling. Be a wise gambler and be responsible with your finances, gambling is just entertainment and gambling is not a machine for getting rich automatically.