"differential" and "differentiable" are different words. Both are being used correctly. Is the problem only that the two words look kind of similar? That seems like an impractical requirement.

Yea, cryptocurrencies will never be known as crypto. The term was coined long ago as a short hand for cryptography.

God I hate the trend of using a prefix on its own as a stand in for '<prefix><thing>'. I think it's a symptom of politicians trying to sound stupid to avoid sounding elitist.

What do you think will have more impact on the economy, crypto or cyber?

I think using the shorten version is perfectly valid only provided the context is correct.

If you are talking to someone about cryptocurrency, referring to it as crypto later in the conversation in context is perfectly valid and doesn't lessen the meaning.

I do however agree with you when outside of it's context that these shortened names are horrible and effectively buzzwords.