It's a little bit funny to me. I can understand a response of "Hmm, while your application of cryptography may have some legitimate uses, in practice it seems like it's largely used for crime and scams." But I wonder what they thought the primary application of cryptography was going to me! Privacy-preserving technologies that allow you to hide from the government are necessarily going to be useful to criminals. But that's the price of freedom, no?
(I guess to be fair, some cryptographers might be interested in things like privacy-preserving voting, which wouldn't ever be useful to criminals.)
Transparency makes it hard for big criminals to move money unnoticed.
Private servers and ledgers make it way easier.
Look at the Epstein case. Convicted sex offender and child trafficker who used JPM Chase for all financials related to the activity, including involving some of the bankers and their clients - and they were able to settle with the Epstein victims for millions. A few others died randomly right after.
That is totally sealed. Unable to be seen by the likes of you and me. Crypto currency would absolutely solve that. It would open up all the transactions and people would figure it out, and dox the pedos.
You could solve all sorts of crime with transparent banking even if it was by and large anonymous.
Classic use cases would be like 1) show that you have a national id (like a passport) without revealing which one, 2) show that you are >= 18 without revealing your date of birth. More generally, assuming you have digital credentials with metadata, pretty much any statement can be proved in ZK (relatively efficiently, especially if the digital id is designed to be ZK friendly).
Did their advancements have any other implications besides cryptocurrency?