Huge capital is usually required in business and not in making a career. Making a career in gambling by doing gambling is insane thinking and i am sure anyone who has been gambling for some time, knows the fact that only luck is the main factor that makes the gamblers successful and no career and business can be built on luck only.
Yes, if you have a lot of capital, why not open your own casino? This is the only possible way where one can get a grantee income but remember, it will require a lot of capital to start such a business and also experience of running a casino also matters a lot.
Unfortunately the ratio of gamblers winning in gambling is low when compared to winning ratio of the house. So its good idea to build a house that will generate a secure income rather then losing all you have in gambling.
We dont have much stories of people who have made fortune out of gambling. That's why its not a wise decision to adopt gambling as career. Gambling should only be taken as leisure activity and its addiction must always be avoided.