But it's quite the opposite of an appeal to ideological purity. If you care about building out widespread truly decentralized cryptography, the practical results of cryptocurrency are nothing short of incredible. Because of crypto, millions of people now self custody their own private encryption keys without any dependency on centralized services. Yes, they're doing so because they want to play in a giant on-chain casino. But the same ECDSA key that secures your Ethereum wallet can also serve as your decentralized cryptographic identity.
It's hard to overstate how much of a miracle this is compared to what anyone expected 15 years ago. Hardcore cryptography engineers would joke about how even their small, highly committed community couldn't build a decentralized a web of trust with decent opsec. Now even dentists are self-custodying their crypto keys with decentralized identity powered by ENS.
Quite the opposite the only reason to dismiss this achievement is an appeal to ideological purity. The cryptography infrastructure may have been built for the "wrong reason", to gamble in the world's largest casino, but a once undreamt of decentralized infrastructure now exists.