There are many people who indulge in gambling activities but I don’t think they gamble as their major source of income. They gamble to add up to their financial status, they play gamble as a side hustle. But in a case whereby the gambling is favoring the person, you don’t expect the person to quit gambling.
This is what many individual on this thread failed to understand, that those who made some income or a living from this industry were those who don't gamble or chase their losses. Most professionals we saw on the list have other sources of income and not just rely on gambling alone. Some of us here gamble as a side hustle, particularly myself.
If thats the case then it cant be tagged as a gambler making money through gambling alone because they are just playing as a sideline to earn extra and not because its their own main source of income. I believe there are professional gamblers (maybe only few) who rely on gambling to make money using their skills and strategy to maximize their earnings. But for an average gambler its quite hard to do it specially if they have no self control, the situation can turn to worse if you cant handle the losses.