Any government should support the desire of households to improve their financial well-being. At the same time, the government should not allow conflict and chaos due to the addiction of its citizens to gambling.
The government of the country should also take care of the moral character of its citizens. Violent and bloody sports should not be encouraged. Here it is necessary to maintain a balance between the interests of different segments of the population.
Those are good points you brought up, and the role of government and the things it should and shouldn't do is (and always has been) a very complex discussion.
However, one point you didn't bring up is cruelty to animals, which many governments have laws against. If you ask me, cockfighting
is animal abuse, though I'm sure there are a lot of members who'd disagree. They're just chickens, right? And I'm by no means a PETA activist, but I consider modern chicken farming to be a form of abuse as well (like packing them together with no room to move, pumping steroids in them such that they gain so much weight that they can't move, etc.).
But hey, that's just me. The government of my country doesn't seem to mind how chickens are farmed, although they regulate it. They do have laws against cockfighting. Not always consistent with their actions or their philosophy, are they?