and most of the time, gamblers want to mind your own business. if he lost, thats all on him. you cant say anything about it or bother him about it. because that's his decision. and so i never tried someone to stop from his gambling activities. it is his own will that can only change his habits.
you cant also persuade someone while he is in the middle of his game. he will more then likely be pissed off on you rather than be thankful. so let them be. their money, their choice!
I agree with you. Plus, this idea as a whole seems illogical to me - if a person is already playing, then he has made a decision and all responsibility is on him. If he is addicted, then none of your arguments can change his behavior - here he needs help from family + specialists.