At the end of the day people have the freedom to use their money as they like, as long as you can cover your basic necessities and those of your family as well then the rest of your money can be used on whatever you like, if someone decides to use some of that money to gamble I do not see anything wrong with it, now it is true there are people which cannot deal with it and end up losing way more money than that and suffer long term negative consequences due to their lack of restrain, but fortunately their number is on the low side.
That is correct people have all the liberty to do what they want to do and how they want to spend their money. But then again sometime a little piece of good advice can help change the attitude and can bring in good change change in the financial habits of the people.