There is a reason Ponzi are criminal. Why else would Bernie Madoff gone to prison? Is it no longer a game when it involves millions of dollars?
The reality is there are no set odds to the "game" of Ponzi because it is stacked against you from the start to only benefit the operator. If you fail to see this, I really cannot explain it any other way.
There is a difference between deceiving people and offering all sorts of "investments" which turn out to be ponzis, and inviting people to gamble money into something that calls itself a ponzi, where the rules are known upfront.
That's the key difference.
When it's calling itself a ponzi, you know that the operator will win in the end--there's no deception in it--not unlike other forms of gambling, really. The only thing that really distinguishes it is that unlike casino banking games, players have an incentive to recruit more suckers so that they aren't holding the bag in the end. Kind of like a stupid form of poker, I guess, where the house rake is huge.
To each his own though.