You know, I kind-of agree with that post. There's no rules against posting "Hey HN, what do you think of this idea?" which is essentially the same thing.
I think there is value in having a consolidation of these threads, though.
I'm actually a big fan of Vault and greatly respect/look up to the Hashicorp team :)
I think Vault can be great for teams that are sufficiently large and sophisticated on the DevOps front. I felt there was a need for more of a Heroku/1Password-style tool for teams that want a secure way to manage secrets without undertaking a big project to setup/maintain their own secrets server.