Giving money to Nigerian princes and joining Amway is also voluntary. That doesn't make either any less of a scam. Scams that prey on people's natural stupidity and greed don't stop being scams simply because the mark isn't robbed at gunpoint.
Nigerian princes promise something that they can't deliver. I don't.
Amway is a perfectly legitimate business by my standards (or at least the concept of Amway -- how they operate is an entirely different matter...).
Some people win, others lose. Gambling as a whole "preys on people's natural stupidity and greed." That doesn't make it morally wrong.
I'm tired of arguing with people like you.
Arguing with me is voluntary, therefore you must enjoy it.
The gambling analogy is a good one. Gambling can be done fairly, but not all gambling is fair. Let's say I create a game with complicated rules that pays out well at first to draw people in but eventually just takes everyone's money, that is a scam. But just because that game is unfair doesn't make poker a scam. See, some things are scams and some things aren't. Ponzi schemes are scams. Puppies are not. Nigerian prince emails are scams. Hugs from your grandma are not.