I'll take a shot at least at refuting the claims in the first bulleted point: "they are deliberately incompatible with the rest of the financial system" so is

I'll take a shot at least at refuting the claims in the first bulleted point: "they are deliberately incompatible with the rest of the financial system" so is the north korean won (or the venezuelan bolivar, or, on the other side of the "good faith" spectrum, the brazilian real at its inception), but you wouldn't claim that they aren't currencies. "Most merchants who accept cryptocurrency aren’t actually accepting cryptocurrency, they’re using a service that turns it into dollars" Arguably the same would be true for certain types of bank notes in the 19th-20th century (like 5k, 10k, notes). Still currency. "they are provably inferior to alternative payment mechanisms." this is basically a concession that it is a payment mechanism, if a poor one.