It's absolutely unwise for a financial dependent to gamble and should be condemned by anyoone who's around such person. Over the years, I've seen very young people who are still surviving with the financial assistance of their parents or guardians use money that was meant for something very serious like school fees, money meant hospital bills and sometimes money that was given to them to go and buy food items using such money to gamble.
They end up losing the financial trust of their parents and guardians because of their very silly decisions to gamble with those money.
I highly agree, those financial dependent found gambling should be condemned and be thought of avoiding gambling activity. If I am the parent, I will ground them cutting their allowances. Since they have the audacity to gamble the money I work hard for, it only means that they are not lacking and maybe I have given them too much making them spend the extra on gambling.
After the duration of grounding and allowance cutting, I will talk to them seriously and tell them the reason of the punishment and make them see the importance of giving value to the money that is given to them.