There are plenty of legitimate scams in the cryptocurrency world, but the games we're referring to (PonziCoin, PoWH3D, CryptoCelebrities, CryptoKitties, etc.) are very transparent about the fact that they are zero-sum games where you have the chance to lose a lot of money.
These games should really be considered simulated bubbles instead of Ponzis. A Ponzi scheme collapses when the operator walks away with everyone's money. PoWH3D doesn't have an operator since it's totally decentralized. It will collapse when everyone decides to sell. Likewise, CryptoCelebrities will never crash but inevitably somebody will get stuck with a collectible that nobody else wants to buy. It's akin to buying a beanie baby or a tulip for an exorbitant price, only to find that there's nobody to resell it to.
These games should really be considered simulated bubbles instead of Ponzis. A Ponzi scheme collapses when the operator walks away with everyone's money. PoWH3D doesn't have an operator since it's totally decentralized. It will collapse when everyone decides to sell. Likewise, CryptoCelebrities will never crash but inevitably somebody will get stuck with a collectible that nobody else wants to buy. It's akin to buying a beanie baby or a tulip for an exorbitant price, only to find that there's nobody to resell it to.