For me gambling could be a profession for sure for a lot of people but it was really risky for a lot of people maybe if you have a lot of money or already have a lot of businesses and passive incomes like apartment or restaurant, you already have a source of income that you could use in gambling and have a chance to win as your profession. But surely if your already a professional in gambling you should not reach the point where already gambling all of your money you should always limit your money to gamble.
The risk is not worth for every people because they need to spend time to learn the skills in gambling. They need to have money to learn the lesson, and they must prepare for the lose that always comes to them at any time. Although you already get passive income, it doesn't guarantee you to have a chance to win in gambling because you know that gambling will be related to luck. It will be difficult to be a professional in gambling because that will need time and learning in gambling, and not all people can do that.