How can one prevent exchange hack through rules and regulations? It can only increase the chance of not getting hacked if the businesses follow some standard security protocol and have adequate insurance cover. 

Also the billboard of Gemini says that,



And after receiving a fair amount of criticism from the bitcoin users worldwide, Cameron came back with the statement that you've mentioned in the thread subject! Cryptos can't be regulated - that's an universal truth! However, I too strongly believe that the business entities must be regulated who are built around cryptos. because the mass adoption can only happen when there is regulation because it brings trust within the system.