Suppose that you are a responsible gambler who have allocated a certain portion of money to gamble each month. Now you came across a poor person/family who is in urgent need of money. Will you quit the gambling for that month and give the allocated money to the poor family or will you prefer to gamble as you can't live without gambling ?
If you are a responsible gambler and moreover a professional gambler, why should stop or quit gambling for a month to give the allocated money to them?
Why we don't change our mind to:
"Doing gambling and try to win gambling, then use the profits to give the poor in a certain amount".
So, your plan to help the poor still can happen and you can still do gambling activities during that month.