If some one has to pay a tax on there gambling addiction then I think it may help them want to start thinking of how to get help so as to not have to worry about it all. I do not think gambling is healthy and some may even consider it dangerous.
Gambling is a private tax and should not be enforced by government agencies. Government agencies are concerned with the caring for the poor with taxes. Also the government is concerned with using politics to ascertain that private citizens pay taxes to help to pay living expenses of those less fortunate.