That's an astute question. I think "crypto" sadly joins the ranks of "cyber" as a technical term that got creatively misapplied, and has been rendered more or less meaningless at this point. Nakamoto simply called it "peer-to-peer electronic cash" that relies on "cryptographic proof" for its trust; as your question alludes to, cryptocurrency is not particularly cryptographic! It relies on public keys and hashing problems, and as you say much of the more interesting technology involved (and subsequently studied) involves distributed systems.

Here's the thing: crypto sounds kind of cool. It's associated in the popular imagination with ciphers and secrets and hacking and spies. And it played really naturally into the perception that Bitcoin, in particular, was somehow private or secret in its transactions. I would suggest that, historically, we see it adopted not as a deliberate way to steal cryptography's scientific valor, but rather as a cool portmanteau that evoked what fairly non-technical people thought of when they thought of cryptography.