That is the silliest point of all, because the concept of fiat currency is inherently associated with its plurality (given that fiat currencies are born out of countries, and there are many countries), but cryptocurrency, as a concept, came to existence to destroy all fiat. And the only way to do that is via 1 single cryptocurrency: the very first, the only one. And this is better understood once you understand this: https://en.bitcoin.it/wiki/BIP_0300 (which is not activated yet, and might never be; but once you understand its purpose, you will understand this HN thread)