Or, by less casual name, "intersubjectivity". And yes, it's a very important idea that directly applies here.
Most fiat currencies impose a degree of solidity by being required for payment for certain services (read: taxes)
But yeah; until somebody gets a different trusted party to look at the item.
Fraud generally pays pretty well until you get caught.
On August 9, 2010, Symantec completed its approximately $1.28 billion acquisition of Verisign's authentication business, including the Secure Sockets Layer (SSL) Certificate Services, the Public Key Infrastructure (PKI) Services, the Verisign Trust Services, the Verisign Identity Protection (VIP) Authentication Service, and the majority stake in Verisign Japan.
I can start a CA tomorrow, doesn't mean anyone will put my root on their OS distro.
No, you make the money by offering to sell real certificates of authenticity to authenticate the fake certificates of authenticity to people who those who calls and asks.
And yes they would want you to say "yes/no, it is/isn't authentic" to anyone who calls and asks.
But if you screw up your records and say "yes" to fake certificates of authenticity that imitate yours then people will stop paying you very quickly. (Also you may end up in jail)