I understand how public-private keys work, and I understand why you’d want one. I just think this implementation of a register is bad. Not from a security risk, from a use case point of view; it’s for all intent and purposes an email which if ever compromised is forever compromised and non reusable. It’s an email that’s unrecoverable so not usable in many companies.
I’m sure there are other reasons to not like the idea, but that’s what I can think off the top of my head.