Using "crypto" to abbreviate "cryptocurrency" causes a lot of confusion, as the "crypto" in "cryptocurrency" was already an abbreviation; "cryptocurrency" is short for "cryptographic currency."
People who know nothing about cryptography or even that cryptocurrency uses cryptography get confused if they are looking for information about cryptocurrencies and instead find more general purpose resources on cryptography (like https://crypto.stackexchange.com/ or https://www.reddit.com/r/crypto/).
I know that this is a losing battle, like getting people to stop using "wiki" as an abbreviation for Wikipedia (which is just one out of many wikis), but I figure that as long as we're talking about people not knowing much but investing in it anyhow, I really encourage everyone to stop using "crypto" as an abbreviation for "cryptocurrency."