Maybe they think that the government allowing gambling will make many people interested in gambling. Moreover, they can win some money from gambling, making them continue to gamble. But actually, playing gambling or staying away from gambling is each person's responsibility. The same as smoking and drinking alcoholic beverages. We already know the dangers of all of this, so we should be able to stay away from it or choose to use it but with limits.
Yes, we should know about limits and use gambling as entertainment. Otherwise, we will suffer losses because we have lost money playing gambling. And we are actually to blame because we have gambled excessively even though gambling is a pleasure that we are not obliged to do. If we gamble within limits, there would not be any problems that would happen to us.
If ever the government will ban gambling, people who want to gamble will eventually find a way to access gambling sites and casinos. They will just be creative in accessing those without the authorities ever finding out about it. People are stubborn especially if they are really that interested and hooked up in betting and playing, they will find ways regardless. It's not as if it will really solve the problem by prohibiting people, it could only be a band-aid solution while the dependency in addiction haven't been addressed yet.
Indeed, gambling is someone's responsibility and not anyone else's. If they don't want to suffer the consequences, then they must do themselves a favor of not spending too much time and money in it. Addiction doesn't just occur instantly, it is a bad habit built over time. So staying away and choosing yourself and your sanity will save you from it. Limiting the engagement by not feeding your thirst to it will prevent you from being addicted.