Matthew Green from John Hopkins University [0]
Zhenfei Zhang of Ethereum, Mina, Algorand blockchains who co-created the NIST post-quantum cryptography standard for digital signatures called Falcon [1]
Nadim Kobeissi creator of cryptocat now created Capsule Social [2]
Silvio Micali, Turing Award Winner for his work on Zero-Knowledge Proofs [3]
So, I'm afraid that there are some credible people like those above who have a significant and documented background in cryptography who are also working in the cryptocurrency industry.
I don't think most of these people are into cryptocurrencies specifically.
They are? Especially the creator of Algorand (a cryptocurrency) Silvio Micali. In his CV [0]
> "Scientific Interests, Cryptocurrencies, Blockchains"
At the bottom of his CV:
> "Technology Transfer: Algorand, Founder and Inventor of the Core Technology"
If that is not 'into' cryptocurrencies, then I don't know what is.