Gambling is not a way of making money and making a living. Taking a risk in a situation like this is foolish. And at this point, it is not even risk. It becomes greed. And we all know what greed does to people. But if you are a person who already have more money to spend on gambling, then I think you can call it a risk. You already have enough and losing that won't affect you.
We can say that it varies from people to people. To some it is greed and to some it is risk. For me, I won't go for either and cash out to enjoy what I have.
First, just as you have tightly said, in Normal circumstances or conditions, taking risk is good for it is the only way we get a chance at making more money, and gambling is not left out in mediums through which people can take risk, but then, I think the problems with most of us is that, we often don't know when a safe risk shifts from we taking risk to become we being greedy. That is, most of us lack understanding of when a risk turns into greed, and this is something we really need to pay attention to as gamblers..
Some risks can really be stupid, and this is the type I personally assume to be greed, though it is true that some people's risk might or can be some other people's greed and verse versa, it all depends on how much money one has and how much he or she can afford to risk and lose in a game, for those that probably have made some money and continue to play, and now, above their normal limits, it's a pure greed on them, and this can cause them to lose even all that they have managed to earn, while for those who win, and still continue to play because, they still have more than enough money that they can afford to lose regardless, it's still a normal risk for them.