Criticizing gamblers for their gambling habits is necessary and yes some of them are not exactly in good mindset and they require much more compassion but we can’t make excuses for them because a lot of them basically just lack some discipline and that’s what they need if they want to keep gambling.
Why you think criticizing gamblers for their gambling habits is necessary? If their are in a pathologic condition, then don't expect any of them to interact with your opinions. Before everything, why you bear such a responsibility if the gambler isn't one of your closed relations? Sometimes, it's not that necessary to give moral advices for others even we are sure they are in real need for it, because they can easily find it a pretext to attack or just to ignore. Just my two cents if you can understand what i wanted to say. No offense.