Success in gambling is based on luck and not determination, unlike some persons that are specifically gambling to fund their bills daily. You could be determined to make income through gambling but losses will knock you down, that's why I really don't think that gambling should be taken very serious as a source of income by anyone. You will just end up to lose your money repeatedly until you are broke.
That's right, someone who has a strong determination and high fighting spirit does not mean they will be able to win gambling easily, I think more people like that are only obsessed with winning so they only focus on winning and don't care about others such as the risk of losing which is actually more likely to happen than the chance of winning.
It is a mistake when gambling is considered serious, because with this it only allows us to do it blindly without thinking about the risk side.