It is not wrong.If you know how to gamble.natural greed from people makes it wrong.
Greed if you see your winnings growing and want some more. Gambling owners only gives you a the table and the game. But they dont give you that greediness and that mind set that if you lose you will come back to get it back.
But that table and game itself is greed for members, they can not resist themselves from playing up with them, unless they loose everything, almost at the end. Yeah only a few members or say gamblers, are able to stop themselves when ever they want and leave off, though.
Lets say is a poker game I think when that game you will be always being greedy, but you need to play smart with it. You can't just stop playing you can stop, but you will lose all your money I think that game is good to know your budget about the game. Lets say roulette I know for sure is really difficult to stop when you are winning. So is all control and the pros knows it.