Gambling is zero sum, so within a closed system, it can never be beneficial. The only way it can be beneficial is if it extracts value from outside of a particular locality and distributed the losses externally. Why vegas or macau can succeed is because most of the gambling in these cities is done by people outside of vegas and macau. If gambling in vegas was confined only to the people of vegas, then vegas would collapse as a portion of their citizens' lives are ruined.

Though I'm personally against all types of gambling, I believe in individual rights and a person's right to waste their money as they see fit. However, I don't think governments should be so closely tied to it and I certainly don't think governments should be depending on it for funding of any sort. They should tax the companies involved in gambling, but they should be "in bed with them" so to speak. And I don't think state governments should be involved in lotteries either. Lotteries should be purely private and the government should tax it. I don't think a moral or sane government that truly cares about and represents their citizenry could be involved in lotteries or gambling.