That's totally unfair.
It was buying all kinds of drugs, and weapons, and child porn, and stolen credit cards, and hiring assassins.
The assassins invariably turned out to be working for the FBI, of course.
It's a tool that can be used for good or evil, just like the personal automobile, which was also abused in early years for malicious ends - just as telephony, the internet, and a number of other technologies were.
Criminals are early adopters of new & emerging technologies, that doesn't make those technologies inherently evil.
Also, why lump drug transactions in with weapons / CSAM / cc fraud / assassinations? Most drug buyers are not hurting anyone.
The marketplace for all of the above (except assassination) was the same - Silk Road. I remember seeing different sections for weapons, credit cards, fake ids and drugs, but I don't remember seeing a section for CSAM unless it was masquerading as something else.
This boils down to two things, really: 1. To skirt the law (aka regulatory arbitrage) and 2. Act as a techno-libertarian “sound money” experiment.
Ghost guns can be used for good. But it’d be pretty silly to suggest that criminals use them because they’re early adopters. Criminals use them because they’re criminals. Sometimes the laws they’re breaking are unjust—but these are just tools for breaking the law.
And just because you can use crypto to buy things legally, there’s virtually no reason to do so, like taking a ghost gun to your local firing range.
Uncensorability is a desireable property for legal adult content producers, who are locked out of many payment platforms despite operating entirely within the law.
Irreversibility is a desireable property for merchants, who are the ones left holding the back when chargeback fraud occurs.
Permissionless nature is a desireable property for those at risk of discrimination from traditional financial institutions. While rare in the developed world for law-abiding customers, there are plenty of countries where people of certain races, religions, and ethnic groups are denied access to financial resources like a bank account because of such factors.
While these traits may be attractive to criminals, especially ransomware authors, they aren't only attractive to criminals, and all of them find demand in law-abiding users, as detailed above.
None of this means that the war on drugs etc was justified or that its implementation did not have serious flaws, just that the drug trade isn't a manufacturer of purely victimless crimes.