The snake oil part comes from the business people, not from the physicist. And anyways, it's not that hard for the physicist to learn that there's no future in

The snake oil part comes from the business people, not from the physicist. And anyways, it's not that hard for the physicist to learn that there's no future in QKD, and indeed, the physicist wants to know that to avoid wasting their efforts. Being a physicist does not preclude knowledge of classical cryptography -- and vice-versa. The credentialist approach we take to all specialty knowledge has its limits, and we must acknowledge that. Credentials do not limit one's expertise, nor really do they prove it.